Almandine (Garnet)Almandine is the most common member of the Garnet group. It is also a popular gemstone and the most widely used Garnet in the gem trade. More gemstones are faceted from Almandine than any other type of Garnet. Only a small amount of Almandine crystals are transparent and light enough for gemstone use; most of the Almandine found is rough and opaque and not gem quality. Some Almandine Garnets display asterism when polished as cabochons, and are known as "Star Garnets".
Almandine is often embedded in a mica schists, and forms very nice matrix pieces with perfectly formed symmetrical crystals. The schist matrix often breaks up due to weathering, resulting in the Almandine crystals breaking loose into individual, perfectly formed floater crystals which may be quite large. http://www.minerals.net/mineral/almandine.aspx OlivineOlivine is one of the most common minerals in the earth, and is a major rock forming mineral. Despite this, good specimens and large crystals are uncommon and sought after. Only few localities yield large examples of this mineral, although small and microscopic grains are found worldwide. Olivine is also found in meteorites, and large grains have been reported in many of them.
Olivine is not scientifically classified by the IMA as an individual mineral species, but is rather recognized as a mineral group with the Forsterite and Fayalite end members. Fayalite and Forsterite create a solid solution series, and most specimens identified as Olivine fall somewhere in between this series, almost always leaning more towards Forsterite with a greater content of magnesium. Pure Forsterite is uncommon, and pure Fayalite is very rare. http://www.minerals.net/mineral/olivine.aspx StauroliteStaurolite was designated the official state mineral of Georgia in 1976. Commonly called “fairy crosses” or “fairy stones,” staurolite crystals are common in northern Georgia and are collected as good luck charms.
(will need to find own info) TopazTopaz is a well-known mineral, occurring in large and beautifully shaped and colored crystals. It naturally occurs in many colors, but rarely in pink, purple, and deep blue. Those colors are formed from lighter-colored stones that undergo irradiation and heat treatment. Topaz from certain localities may also turn pink or colorless upon heating. The color of some Topaz specimens, namely those from Siberia, fade upon prolonged exposure to light.
Topaz crystals in a matrix are rare and very much desired, since the perfect basal cleavage of Topaz causes it to separate from its base and form loose crystals. Precautions must be taken not to damage specimens, for pressure or improper faceting can cause a crystal to cleave and become ruined. |