Gemology

Welcome to Mystic Wynd's Guide 
to Gemstones and Their Properties. 
Copyright 2011 Mystic Wynd Creations, All rights reserved
(I'm in the process of building this guide, so please be patient - it'll be worth it!)

Beryl -  A mineral family that includes emerald, aquamarine, heliodor, and morganite. In its pure form, beryl is colorless (goshenite), but the addition of metals cause the stone to take on a wide array of colors. For example, beryl with chromium content produces emeralds, while the presence of iron in beryl is responsible for the lovely blue of aquamarine (although most aquamarines are heat treated to enhance the color). Crystals are transparent to translucent, lack good cleavage, and rank at 7.5 -8 on the Moh's hardness scale. Some of the largest and most well known deposits are in Columbia, Brazil, Central and West Africa, Madagascar, Russia, the Ukraine, and the US.

Chalcedony: A variety of Quartz, often combined with Mogánite, another silica mineral. When chalcedony appears with concentric bands in either circular or freeform patterns, it is classified as the sub-variety Agate. When it appears in flat layers or band, it is classified as the subvariety Onyx.

Occasionally, the term agate is applied to non-banded forms of chalcedony such as Moss Agate or agatized wood (petrified wood) which has the appearance of concentric bands, but in this case the banding is caused by crystalline deposits in the tree rings, not free crystalline formation. In both of these cases, a more appropriate label would be chalcedony. Other gemstone belonging to this variety of quartz are aventurine, carnelian, chrysoprase (prase), heliotrope, and mtorolite.

Having a mohs rating of 7, this moderately hard stone appears in a wide variety of colors with white, grey, grey-blue, green, brown, or black being most common.  Chalcedony deposits have been found on all of the world's continents.

Feldspar - The most common rock-forming mineral group comprising nearly 60% of the earth's crust. Having good cleavage in two directions and a Mohs' hardness index of 6, feldspar minerals are usually white or very light in color. Plagioclase feldspars are sodium or calcium aluminum silicates including stones like labradorite, while Potassium feldspars are potassium aluminum silicates including stones like amazonite.

Quartz - Second most abundant mineral/gemstone species on Earth. It has a crystalline structure and many varieties of gemstones belong to this species, including agate, chalcedony, amethyst, onyx, and citrine, to name just a few.
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