Kunzite: Kunzite is the pinkish lilac variety of the spodumene. These crystals or stones have a light pink hue because they constrain, traces manganese. Kunzite was first discovered in California in the early 20th century, and is known for its pleochroism. Its been noted that prolonged exposure to uv or solar lighting will diminish this stones color. This stone is generally sought after for its properties (read full)

Chatoyant Quartz: When quartz contains similarly-oriented fibrous inclusions, and is then appropriately-cut, in cabochon, curved stones display what is known as chatoyancy, meaning 'like a cat's eye.' The result is a series of minor gemstones differing only in their ground color and the mobile reflection. Comes in colors white, gray, green, yellow, brown. When the ground color is greenish-gray or green, the gem (read full)

Emerald: Emerald is the most prized variety of the mineral Beryl. It sometimes fetches higher prices than diamond. It appears as pale green to bright green. Though it is the green variety of beryl, not all gem-quality green beryls are called emeralds; yellow-green stones are called "heliodors;"soft blue-green or even pale green specimens are called "aquamarines." The typical color of emerald is a bea (read full)

Turquoise: Turquoise is a hydrated phosphate of copper and aluminum in the Phosphates, Arsenates, Vanadates group, with a triclinic crystal system. It rarely occurs as prismatic crystals. It is usually found as light-blue or green masses, nodules, and veins, sometimes filling cavities in various rocks. When it occurs as thin strips, it is tighter and brightly-colored at the center, lighter and porous on the (read full)

Lapis Lazuli: Lapis lazuli is composed of several minerals in small quantities - augite, calcite, diopside, mica, hauynite, hornblende, pyrite. Because of this some experts consider it a rock, more than a mineral. The main ingredient of Lapis lazuli is Lazurite. It has a uniform, massive, or sometimes granular appearance, with fairly distinct crystals. It is semi-opaque to opaque, with a surface that can take (read full)

Labradorite: Labradorite is a sodium-rich plagioclase feldspar which displays a particular type of iridescence on a dark ground. Plagioclase feldspars are rock-forming, calcium-sodium minerals which form a continuous series ranging from albite, through oligoclase, andesine, labradorite, and bytownite to anorthite. Precise classification is generally not possible in hand specimens, and their physical properties (read full)

Diamond: In fact Diamond is the only gem material comprised of a single chemical element: pure carbon, like graphite. But the atoms in diamond have been forced into a compact, three-dimensional structure by the high pressures in the upper mantle, where it is formed. Thus diamond is much harder and has a higher specific gravity (3.52) than graphite . There is nothing comparable to it in hardness; it is ther (read full)

Coral: Corals are the supporting framework of small polyps. Each coral polyp, a tiny marine animal that lives in enormous colonies, extracts calcium carbonate from the sea and exudes it through their bases to build a protective home around and above itself. Each generation of polyps dies in its protective home and each succeeding generation builds on top of its predecessor. They precipitate calcareous m (read full)

Alexandrite: Alexandrite is one of the more rare varieties of color changing chrysoberyl that changes color depending on the type of light that hits it. In daylight it generally appears greenish, while it appears red while indoors due to the incandescent lighting. This gem was first discovered in the Ural Mountains of Russia in the 1830s, but has since been found in Sri Lanka, Brazil, and even East Africa. (read full)

Euclase: Euclase is a silicate with a monoclinic crystal system. It is considered a very rare gem of light blue color. It appears as long or short prismatic crystals, flattened and transparent. It is colorless, white, green, or blue, commonly a pale aquamarine or green, but crystals of a very fine dark blue (from iron) have been found at the Miami mine in Zimbabwe. Crystals are often striated. It (read full)

Ruby: Ruby is the most valuable variety of Corundum. The color varies from fiery vermilion to violet red, but because rubies are pleochroic, different colors are also found in the same stone; bright or sometimes brick red in one direction, tending to carmine in the other. The color is also accompanied by marked fluorescence which is stimulated by ordinary, artificial light, and above all, by the ultra (read full)

Sard: Sard is the uniformly colored red-brown or brownish-yellow variety of Chalcedony, which in turn is a microcrystalline variety of Quartz. There is no strict separation between sard and cornelian/carnelian (red to reddish brown), because they are both chalcedonies found in the same deposits and were employed for the same objects. The tints of a sard stone may be reddish or orange. Good-quality mat (read full)

Fire Agate: Fire Agate is a term applied to much of the variety of chalcedony that occurs as botryoidal, consisting of crystals of minute platy inclusion of an iron mineral goethite or limonite minerals over the layers of chalcedony, producing a vivid rainbow containing every color in the spectrum, an iridescent, fire-like appearance, with careful polishing away of the brown outside layers. When polished, it (read full)

Scheelite: Scheelite is a mineral in the group of Sulfates, Chromates, Molybdates, Tungstates. It has the same crystal structure and outside appearance as powellite. But scheelite is a calcium-tungstate, while powellite is a calcium-molybdate.

In rocks, scheelite may appear as crystals like two pyramids connected at its bases, or pseudo-octahedral, or having table-like faces, with detectable p (read full)

Sapphire: Sapphire is the blue variety of Corundum. Sapphires can be a very dark blue, to the point of seeming dense and blackish from a distance, sometimes accompanied by a blue to dull green pleochroism, which is only visible from the side in cut stones. They may also be a strong, but not too bright blue, easily recognizable from a distance, this being the real color. Other possibilities are light, usual (read full)

Sunstone: In its raw form, sunstone forms as translucent to transparent crystals with distinct cleavage planes and a vitreous luster. The unpolished specimens display copper platelets that catch light even through the rough surface, creating scattered copper-red flashes. Once cut and polished, sunstone truly comes alive - skilled lapidaries often favor oval or cushion cuts that maximize the stone's aventure (read full)

Calcite: Of all minerals, calcite is by far the richest in forms. It appears as rhombohedral, scalenohedral, or prismatic crystals, often intergrown or twinned. It occurs in masses, colorless or in white, pink, green, or yellow, and often visibly thermoluminescent (emits light when heated). Like quartz, calcite often has twinned structure caused by temperature and stress changes. It is semi-hard, wit (read full)

Larimar: Larimar is a rare blue variety of pectolite found only in the Dominican Republic. Its distinctive sky-blue color comes from copper substitution in the mineral structure. Discovered in 1974, it's nicknamed "Caribbean gem" or "Dolphin stone." Used mainly in jewelry, its color can range from light sky blue to deep blue with white patterns. Mining occurs in a single mountainous region of the Dominican (read full)

Spinel: Spinel is an extensive group of minerals in which magnesium may be replaced with iron, zinc, and above all, manganese. The hardness and fine colors of gem quality spinel, known as Noble Spinel, set it apart as a gem material from other types of spinel. It normally occurs as distinct octahedral crystals, as clusters also of octahedral habit, or as characteristic twins. The crystals are often iso (read full)

Brazilianite: Brazilianite is a soft and brittle mineral that in general does work very well as a gemstone. It's soft at 5.5 Mohs, and so it will quickly either shear apart, or crumble at the edges. As one might guess Brazilianite was first discovered in Brazil. It tends to be a yellow or light yellowish green mineral. This mineral has also been found in New Hampshire, United States. The mineral is so rare it (read full)

Opal: Opal is hydrated silicon dioxide. It has the same chemical composition as quartz but contains about one-tenth (and sometimes as much as one-third) water. It is never crystalline, but it displays a rich play of colors, or "fire" caused by the internal refraction of light by the array of tiny spheres of amorphous silica which for a compact, three-dimensional network in the mineral. It may be somew (read full)

Serpentine: Serpentine may refer to a single mineral but more often to a group of minerals including antigorite, chrysotile, clinochrysotile, and lizardite, which are altered products of basic and ultra-basic rocks. Rock composed of these minerals is called serpentinite. It comes in all the hues of green.
In mineralogy, serpentine is divided into three polymorphs, crystals with the same chemical substanc (read full)

Lazulite: Lazulite is a compact, pleochroitic mineral which forms a series to scorzalite. It is dichroic, with a monoclinic crystal system. It appears as pointed, pseudo-dipyramidal, bright blue crystals in microgranular masses. It is hard, medium heavy, fragile with indistinct prismatic cleavage. It is translucent, with vitreous luster. It is infusible, discolors and breaks into small fragments when heat (read full)

Andalusite: The gem Andalusite is a gemstone composed of Lead Sulphate giving it a yellowish hew with a light tint of a rusty red color. Its named after the city Andalusia in Spain where it was first found. Colors generally vary from yellow, to yellow green, to green, to brownish red (more iron in the read hued versions), to purple, and even black. This gem is pleochroic meaning it changes color depending on (read full)

Moonstone: The variety name Moonstone is usually used to describe an optical effect and unlike most variety names it is not confined to a single species (The term is also applied to albite-moonstone, microcline-moonstone, labradorite-moonstone). But Moonstone most prominently refers to the orthoclase feldspar, Adularia Moonstone, a microperthitic association of orthoclase and albite) and rarely to Albite M (read full)

Apatite: Apatite is a gemstone that appears similar to tourmaline in its blue green form. It comes in yellow, green, pink, purple, violet, clear, and cat's eye. The most popular and valuable versions of Apatite are currently the blues that look like tourmaline. In fact its Greek name means "cheat" because it's often passed for other more valuable gems. Apatite streaks white to white yellow. The light gre (read full)

Sinhalite: Sinhalite is a magnesium aluminum borate, and is most commonly found as transparent honey-yellow to brown grains or pebbles with an orthorhombic crystal system. It also appears as pale yellowish, yellow, brown, greenish-brown to black. It occurs in contact metamorphic rocks that are rich in boron, among gneiss or granite where limestones are being replaced through contact with magmatic rock. But (read full)

Enstatite: Enstatite is the most common silicate under the Orthopyroxene group in the larger classification of Pyroxene minerals (which are rock-forming silicates). Orthopyroxenes form a chemical series composed of the magnesium-rich enstatite, and the iron-containing bronzite and hypersthene. It has an orthorhombic crystal system and appears rarely as stubby, prismatic crystals, but more commonly in fibr (read full)

Rose Quartz: Rose quartz is a usually cloudy, translucent, delicate pale pink, deep pink, rose-red to quasi-white and often veined variety of Quartz. Also known as pink quartz , rose quartz may occur more often as anhedral masses or rarely as crystals which often reach quite large sizes. Rose quartz almost always occurs in pegmatites in massive crystalline bodies which do not show crystal faces. These larg (read full)

Oligoclase: Oligoclase is a mineral of the plagioclase feldspar series, other members of which are Labradorite and Anorthite. It forms as tabular crystals, which are commonly twinned, with parallel or criss-cross twinning striations. It appears as massive, granular, or compact. It may show brilliant reflections from inclusions. It is light, transparent to translucent, with a vitreous luster and may come in (read full)

Indicolite: Indicolite is the blue sodium-rich variety of Tourmaline, and may come in all shades of blue, from light-blue, violet-blue to deep red or deep green. It generally appears quite a deep blue, even the color of dark blue ink, perhaps appearing green in one direction because of its strong pleochroism. Sometimes indicolite is an overall greenish blue, which, unlike the color of greenish blue sapphire, (read full)

Celestine: Celestine appears as colorless, or pale blue, and is transparent to translucent, and has two directions of cleavage. It is very brittle, and has a vitreous to pearly luster. It occurs in sediments associated with sulfur, with evaporate minerals like gypsum, anhydrite, and halite; in hydrothermal veins with galena and sphalerite; as concretions in clay and marl; in cavities in basic lavas, and i (read full)

Scapolite: Scapolite is a mixed crystal series, a complicated sodium calcium aluminum silicate group composed of calcium-rich meionite, and sodium-rich marialite. It appears as yellow, blue, pink, violet, or colorless prismatic crystals with a tetragonal system, mostly surface-growing, with perfect cleavage. These crystals are usually in aggregates that are massive granular, long columnar, dense, with vitr (read full)

Goshenite Beryl: Goshenite is a colorless sodium-rich gem variety of Beryl, a group which includes Emerald and Aquamarine. Other gem beryls include Heliodor and Morganite. It also appears are pale-green, apple-green, to bluish. All beryls are resistant to chemicals with the exception of fluoric acid. They are brittle and therefore easily damaged by knocks, have a vitreous luster, and occur with aquamarine. Their (read full)

Aquamarine: Aquamarine is a form Beryl that is similar in color to sea water. So it varies from green to blue just like the oceans. Most if not all Aquamarine has been heat treated to improve or lighten the color. Currently the most popular and therefore valuable colors of Aquamarine Beryl are the light "sky" blue versions. If Aquamarine receives large amounts of heat treatment it will bleach or be (read full)

Danburite: Danburite is a silicate of clear, prismatic crystals, with wedge-shaped terminations. It is occasionally pale yellow, a variety of gemstone feldspars group that resembles topaz. It is very hard, heavy, and has a transparent to vitreous to greasy luster. It fuses easily into a colorless glass, coloring the flame green, has a luminescence that is sky blue to pale blue-green, and also shows red therm (read full)

Phenakite: Phenakite is a rare beryllium silicate with a hexagonal crystal system. It an attractive hard mineral that resembles quartz. It appears as white or colorless rhombohedral crystals or stubby prisms terminated by multiple rhombohedral faces. Twinned crystals are also common. It may be colorless, yellow, pink, or brown. There are occasional chatoyant specimens, and four-rayed star stones with a brow (read full)

Phosphophyllite: Phosphophyllite is a very rare mineral, a hydrated zinc iron manganese phosphate with a monoclinic crystal system. It appears as long prismatic or thick tabular crystals. It is colorless to deep bluish-green. Polysynthetic twinned crystals are common. It is semi-hard, light, with excellent prismatic cleavage. Translucent to transparent with vitreous luster. It turns gray and loses water when hea (read full)

Gypsum: Gypsum is the most common sulphate mineral. It is usually the first evaporite mineral to be precipitated form water due to its poor solubility. Varieties include Selenite (or "spectacle stone), which is colorless and transparent; Satin Spar, the fibrous, translucent form with silky luster, which when cut cabochon shows pearly chatoyant effects; Alabaster, used for ornaments, which is firm, fine-gr (read full)

Andradite: Andradite is a name given to members of the garnet that contain manganese and titanium. The 3 types Andradite are..1.)Demantoid, 2.)Melanite, and 3.) Topazolite Demantoid-the word means diamond like. It is yellow green to green in color and is the most valuable of the 3 types. Demantoid is soft enough that older gems will have facet edges that are slightly worn. Largest deposits (read full)

Chrysoberyl: Chrysoberyl appears as prismatic, tabular crystals often v-shaped twins forming pseudo-hexagonal crystals. Single crystals are rare. May be colorless, green, yellow, gray or brown. A variety, alexandrite, is red in tungsten light but dark green in daylight. This pronounced color change is highly-prized, and the exact tone of colors is important, the ideal being brilliant green turning to fie (read full)

Carnelian: Carnelian is a variety of chalcedony, which is translucent and is red to reddish-brown. It may also occur as flesh-colored chalcedony, known as cornelian or carnelian. It is slightly similar in appearance to its relation, the dark brown chalcedony, sard. The colour of cornelian is caused by colloidally dispersed hematite. Other reddish chalcedonies may have been colored by heating since if they (read full)

Smithsonite: Smithsonite is a mineral in the group of Nitrates, Carbonates, Borates, with a hexagonal crystal system. It appears uncommonly in rhombohedral or scalenohedral crystals. But most of the time it appears with curved faces, like a thick creamy aqua-green mixture poured on rock and left to aggregate in clusters shaped like bunches of grapes, rounded, kidney-like, or to form like elegant icicles, and (read full)

Hauyne: Hauyne is a blue feldspathoid rock-forming mineral, one of four members of the sodalite mineral group that is a component of lapis lazuli. The other three are lazurite, sodalite, and nosean. It is a complex mineral of sodium, calcium, aluminum silicate, and sulfate. Hauyne forms very bright and attractive though uncommon transparent blue dodecahedral or pseudo-octahedral crystals of the cubic sy (read full)

Cassiterite: Cassiterite may form as short or slender prismatic, or bipyramidal, elbow-shaped crystals. It has a crystal surface reflecting light as in a mirror. They may occur as massive, granular, botryoidal, and reniform. When found in granular, banded, fibrous masses, it looks like wood. When found in groups of large bright crystals, it is usually called "diamond tin." A red variety cut for collectors is k (read full)

Meerschaum: Meerschaum is a clay-like hydrous magnesium silicate. It has no crystals, and occurs as earthy aggregates, porcellanous masses, nodular, and porous. In the fresh state it is soapy and soft, but hard when dried. It sticks to the tongue and its taste sets the teeth on edge. It is opaque, has flat conchoidal, earthy fracture, and an orthorhombic microcrystalline system. Because of its high porosity (read full)

Obsidian: Obsidian is an extrusive igneous rock, a volcanic glass formed by rapid cooling. Its essential component is glass. Its accessory components are magnetite, ilmenite, oxides and other minerals, such as feldspar. It has the same composition as dacite or rhyolite, with less than 1 percent water. Its color is shiny black, with clear conchoidal (shell-like)fracture, its texture glassy with rare micr (read full)

Heliodor Beryl: Heliodor is a gem variety of Beryl with golden-yellow or light yellow-green color. In many cases heliodor is also used to include gems known as Golden beryl/ Golden emerald, though not to be confused with gold beryl. It is sometimes hard to establish a dividing line between heliodor and golden beryl. Its main characteristic is its color, which is the yellow-green of olive oil. Its pigment is uran (read full)

Taaffeite: Taaffeite is a very rare beryllium magnesium aluminum mineral. No other mineral has both beryllium and magnesium in its composition. It is one of the few gems to be discovered as a faceted stone instead of a rough, as most gemstones are. Rarely cut as a gem, taaffeite looks like a mauve-colored spinel, and its absorption spectrum is similar to it. But gemologists know they've found taaffeite when (read full)

Kornerupine: Kornerupine is a rare magnesium aluminum borate silicate which occurs as transparent prismatic crystals of the orthorhombic system. It is hard and a has good cleavage in one direction. Colours include a characteristic dark green leaning to brown and a rare and attractive bright vanadium green. This pleochroic colours are brown to greenish brown. Chatoyant stones show a bright eye against a dark g (read full)

Hypersthene: Hypersthene is an important iron-rich orthopyroxene in the Pyroxene group with an orthorhombic crystal system. Other orthopyroxenes forming a complete chemical series with hypersthene are enstatite and bronzite. When the iron content of enstatite increases than it is converted into hypersthene, therefore it is opaque. Pyroxenes are a widespread group of rock-forming silicates. Hypersthene (read full)

Cerussite: Cerussite is a colorless carbonate of the aragonite mineralogical classification. It appears as colorless or white crystals with grayish tints, elongated and generally twinned to form a reticulated network with 60-degree angles, as stubby, tabular crystals in star- or heart-shaped twins. It can also be grey, greenish, or blue as a result of inclusions, such as lead, or copper. Impure cerussite is (read full)

Citrine: Citrine is an attractive type of quartz, which is the commonest mineral on the earth's surface. But citrine itself is an uncommon macrocrystalline variety. Its yellow color brought about by its iron hydrate content, its reddish yellow from a trace of ferric iron. It forms hexagonal prisms, terminated by pyramidal shapes. Its faces are often striated, and the crystals twinned and distorted, having (read full)

Iolite: Iolite is the violet-colored variety of Cordierite (named after French geologist P. Cordier), a silicate of aluminum and magnesium, with an orthorhombic crystal system. Though the name cordierite is used by mineralogists, the name iolite has become established among gemologists. It appears as stubby, prismatic crystals, pesudo-hexagonal twins with a glassy appearance. It is frequently microgranul (read full)

Zircon: Zircon is a zirconium silicate with a tetragonal crystal system, and also contains thorium and uranium. It appears as stubby, prismatic, isolated or sometimes dipyramidal, like two pyramids connected at their bases; or in twins, colorless to yellow, red, brown, gray or green, in irregular granules. It is very hard, heavy, with indistinct cleavage, and shell-like fracture. It is sometimes perfect (read full)

Tugtupite: Tugtupite is a mineral closely related to sodalite and hackmanite, all cyclosilicates whose structural silicate tetrahedrons are arranged in rings. It is also called beryllosodalite and reindeer stone, and crystallizes in the tetragonal system. It is found in fine-grained aggregates of crystals with its own distinctive cyclamen colour. Crystals are very small, tetragonal, almost cubic, or as shor (read full)

Rubellite Tourmaline: Rubellite is the pink to red variety of Tourmaline, which is a complex borosilicate of aluminum and alkali, with iron, magnesium, and other cations. It is found as fine acicular crystals in rocks, or as large individual crystals grown upon matrix where they may reach a weight of several kilograms. Most form elongated and striated trigonal (three-sided) prisms and these are terminated with trigona (read full)

Hessonite: Hessonite is the brown-orange variety of Grossular, a nesosilicate in the Garnet group, with an isometric crystal system. It appears with dodecahedral or trapezohedral crystals, cinnamon-brown to orange because of its iron content. Its color matches that of the oil of cinnamon. It also appears as golden-yellow, yellow-brown, or reddish-brown. It is very hard, heavy, fragile, has no cleavage. It (read full)

Ivory: Ivory is an organic gem material, largely obtained from the tusks of African and Indian (Asiatic) elephants, but also from the teeth and tusks of the hippopotamus, walrus, and other mammals. Like bones, it consists mainly of calcium phosphate in the form of oxyapatite and a small quantity of calcium carbonate, bound together by large amounts of the proteinaceous organic substance dentine, to form (read full)

Kyanite: Kyanite is an aluminum silicate that occurs as elongated and tabular in groups of light-blue crystals darker toward the center, or flat, bladed crystals in schists and gneisses, or as radiating rosettes in quartz. It is trimorphous with sillimanite and andalusite. Kyanite is also known as disthene, meaning, "double strength." This refers to the fact that the hardness along the length of kyanite c (read full)

Gold: Gold is a Native Element that appears in very rare, small, octahedral, cubic, and dodecahedral crystals. It normally occurs in very small, shapeless grains, sheets, and flakes. Dendrites are rare. Nuggets are common in alluvial or glacial deposits. It is of yellow color, varying in brightness, depending on the impurities present. This bright, rich yellow is resistant to tarnishing. Gold is often (read full)

Epidote: Epidote is widespread, forms a continuous series of minerals, ending with clinozoisite, which contains no iron. It occurs as crystals elongated and often striated parallel to length, and also as massive, fibrous, or granular habits. Epidote has a yellow-green color, ranges from yellowish-greenish to greenish-black. It has vitreous luster, and is transparent to nearly opaque. It has one perfe (read full)

Hematite: Hematite is considered the most important Iron Ore mineral. Its crystals appear as reasonably thick. They may be tabular, or rhombohedral, and occasionally prismatic or pyramidal. Tabular crystals may form as rosettes, when they are called "iron roses." It also occurs as massive, compact, columnar, fibrous, reniform, botryoidal, stalactitic, foliated, and granular. When hematite forms in a renif (read full)

Jet Lignite: Jet is an organic gem material composed of lignite, and is a bituminous coal which can be polished. It is compact, homogeneous, has a hard, glossy surface and black interior variety of fossilized lignite or coal. It is an opaque black coalified fossilized drift wood from the coniferlike, 180 million years old 'Araucaria' or monkey puzzle tree that has been dried and fractured following death of (read full)

Sillimanite: Sillimanite is a grayish-blue aluminum silicate with an orthorhombic crystal system. It is trimorphic with andalusite and kyanite. All three have the same chemical compound but their atoms each arrange to create three different crystal forms. It appears as long, slender crystals without distinct terminations, in off-white, gray, brown, pale green, slate-blue, blue-green, and these crystals are of (read full)

Titanite: Titanite is a very rare calcium titanium silicate that is an important ore of titanium. It is also called Sphene. Its crystals are very rare, brilliant, and sparkles like diamond. It appears as crystals that are prisms with pyramid tips, or stubby, wedge-shaped, flattened crystals, or tabular and platy. There are also titanite crystal twins that have grown side by side or interpenetrated, or in g (read full)

Sphalerite: Sphalerite is a zinc iron sulfide mineral formed in an isometric system. It is trimorphous with wurtzite and matraite. All three have the same chemical compound but crystallize in three different forms. The most common crystal forms of sphalerite are in dodecahedrons and tetrahedrons, elegant three-sided formations, often twinned, and otherwise usually massive, thus looking like brownish-black or (read full)

Sodalite: Sodalite is a sodium aluminum silicate chloride in the Sodalite group with an isometric crystal system. Its royal blue forms are the best known. As a mineral, it is a principal component of lapis lazuli. It appears very rare as dodecahedrons, crystals with 12 faces, but usually it shows as compact masses, bright blue, white or gray with green tints. It is unsaturated and rarely appears with inclu (read full)

Jasper Chalcedony: Jasper is the opaque form of Chalcedony, the microcrystalline varieties of quartz that form concretionary deposits, partially of organic origin in the case of jasper. It is commonly microscopically fibrous, massive, and has a nearly wax-like luster. It has a lower density than ordinary quartz. It is the archetypal collectable beach pebble, dense, fine crystalline, translucent to opaque, and cons (read full)

Rhodochrosite: Rhodocrosite is a manganese carbonate, a mineral of the calcite series with a hexagonal crystal system. It is isomorphous with calcite and siderite. It occurs as semitransparent, rhombohedral crystals with poor luster, frequently saddle-shaped, growing into druses, or as concretionary masses, sometimes with irregular, contorted veining. It has low hardness and perfect rhombohedral cleavage. Norm (read full)

Spessartine: Spessartine is the manganese-aluminum variety of Garnet, belonging to its sub-group of aluminum garnets. Garnets are a group of silicate minerals that all crystallize in the isometric system and have the same chemical formula, but in a diversity of proportions, so garnets show up as different varieties, in a broad range of environments. Spessartine possesses the form typical of garnet crystals, w (read full)

Fluorite: Fluorite is a widely-distributed mineral in the Halide classification, and is now mined in vast quantities. It is a suitable mineral for collectors and is rarely cut as a gem, but massive varieties are carved as ornamental objects. It appears in cubes, octahedrons, dodecahedrons, while other forms are rarer. Compact, banded, and concretionary masses are frequently found. Most fine crystals of flu (read full)

Grossular Garnet: Grossular is a nesosilicate in the Garnet group, with an isometric crystal system. Together with uvarovite and andradite, the three are known as the "ugrandite garnets," an isomorphous series of calcium garnet minerals. It appears with dodecahedral or trapezohedral crystals of various colors; normally characterized by a green color, but also may be colorless, pale green or milky when pure, cinnam (read full)

Topaz: The transparent, colored crystals, which also have good luster, are widely used as gems.
Topaz is a silicate of aluminum containing fluorine and hydroxyl which occurs in a variety of delicate colors, nicely added by impurities. It is often found in short to long crystal prisms with pyramid-shaped ends, or just clean finished edges. It is often white, semiopaque, milky, or a faded yellow, (read full)

Zoisite: Zoisite is a hydrous calcium aluminum silicate in the Epidote group, with an orthorhombic crystal system, three crystal axes at right angles to each other, all of varying lengths. It appears in elongated, prismatic crystals, with fine parallel lines on the prism faces and usually poorly terminated. It also appears frequently in formless grains, poorly-defined crystals, rodlike aggregates and gran (read full)

Pyrope: Pyrope is the iron magnesium and aluminum silicate of the pyrope-almandine series in the Pyralspite group of the Garnet family. Its beautiful deep-red gem quality makes it one of the most popular. Pure pyrope is colorless, but its red color, sometimes very bright, is due to small quantities of chrome in the crystal structure. It appears as dodecahedral or trapezohedral crystals, dark red, usually (read full)

Shell: Shell is the hard, protective, outer layer covering of certain creatures found in saltwater or freshwater, such as mollusks, snails, and turtles. This layer consists of calcium-carbonate and chitin, secreted by the soft tissue mantle of most mollusks. The inner surface of the shell is made from smooth nacre which covers the mantle.
Shell is used as inexpensive material for various purposes (read full)