Rose Quartz is a mineral with a hardness of 7 out of 10 on the Mohs scale of mineral hardness [?]. These Trigonally structured gems are made of silicon dioxide, their full chemical compound being SiO2.
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 large masses are practically never transparent, in fact they are usually intensely fissured, crackled, and transected by milky quartz stringers. The rose color is caused by a charge transfer between titanium and iron. Rose quartz may show a strong pleochroism in different shades of pink.
For the same reason almost all rose quartz specimens contain oriented inclusions of the mineral rutile, titanium dioxide, (frequently sillimanite needles, which are known as fibrolite), in needles so fine that they cannot be seen even under a microscope. These inclusions are responsible for the milkiness of rose quartz. These rutile inclusions are known as sagenitic, fleches d'amour, cupid's darts, and Venus hair.
When suitable rose quartz is cut cabochon or in spheres, and light, coming particularly from a point source, is directed onto the sphere, a star of six or more rays (diasterism) can be seen. The position of the star appears to change as the sphere is rotated. Asterism is better known in rubies and sapphires.
Specimens of rose quartz may fade. It is believed that the fading rose quartz is caused by phosphate impurities.
Rose quartz is found either as large crystals or masses. Massive rose quartz comes mostly from Brazil, Madagascar, Namibia, Japan, India, Russia, and the USA.
Rose quartz in euhedral crystals is extremely rare and has been known in significant amounts only since about 1960. The crystals, rarely more than 1cm in size, are of hydrothermal origin. They are found growing on colorless quartz, and sometimes overgrown with bladelike crystals of eosphorite in the pegmatites of Sapucaia and Aracuai, Minas Gerais (Brazil).
Specimens deserving a particular mention are found in the pegmatites of Madagascar and those in Brazil, in particular in the state of Rio Grande do Norte.
With star ruby, star sapphire, petrified wood-star, and garnet star, rose quartz is an example of an "asteriated stone," a stone, which exhibits a star, by either reflected or transmitted light.
Misleading terms for rose quartz include:
American ruby - a misleading term for rose quartz from Arizona and New Mexico.
Anacona ruby - a misleading term for rose quartz.
Ancona ruby - a local, misleading term for a reddish or brownish quartz (rose quartz), colored by iron from Ancona, Italy.
Misleadingly called Bohemian ruby. Also called rosy quartz. Misnomerly called Bohemian ruby, American quartz, Ancona quartz. A misnomerly commercial term used by jewelers as Bohemian ruby when cut as a gem.
The specific gravity [?] for Rose Quartz is 2.65, its refractive index [?] is 1.54-1.55, and its double refraction [?] is 0.009.
History
The usually pale rose color, occasionally an intense rose red, gave the Rose quartz variety its name.
Industrial Usages
Rose quartz is the variety that is somewhat brittle. It is cut cabochon, carved as netsuke, beads, ornamental objects, tumbled, fashioned into pendants, and prized by collectors. It is valued as an ornamental material for its very attractive color and comparative rarity, but this is offset by its tendency to be brittle. Only the larger clear pieces can be faceted.
Rose quartz is used to imitate star sapphire. In some materials can be seen several cracks.
It is frequently dyed with aniline. It is imitated by glass designed to simulate not only the color, but the internal streaks. This process, however, often produces air bubbles, clearly visible under a lens.