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)

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)

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)

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)