Gemstones (Part 1)
A gemstone is a mineral, rock (such in the case of lapis lazuli), or petrified material that when cut or faceted and polished is collectible or can be used in jewelry. Others are organic (such as amber, which is fossilised tree resin, and jet, a form of coal). Some gemstones which may be generally considered precious or beautiful are too soft or too fragile to be used in jewelry (for example, single-crystal rhodochrosite) but are exhibited in museums and are sought by collectors.
Characteristics and classifications
Gemstones are described by gemologists using technical specifications. First, what is it made of, or its chemical composition. Diamonds for example are made of carbon (C), rubies of aluminium oxide (Al 2O 3). Next, many gems are crystals which are classified by crystal system such as cubic or trigonal or monoclinic. Another term used is habit, the form the gem is usually found in. For example diamonds, which have a cubic crystal system, are often found as octahedrons.
In our next issue we will learn more about Gemstones, or please visit our Beading Newsletter Archives section located at the left hand side of our homepage or simply click here…
Read More…
[Source: Beads and Beading Blog]