Agate as well as Chalcedony are a variety of cryptocrystalline quartz gemstones composed of layers of quartz, sometimes of different colors. Agate usually occurs as rounded nodules or veins. The layers of quartz are often concentric. The composition of agate varies greatly, but silica is always predominant, usually with alumina and oxide of iron.
All colors are seen in this wonderful ornamental gem.
You will find banded agate, moss agate, a fascinating white or milky agate that looks as though it actually has black, brown, or green moss growing within; eye agate, which has an eyeball effect; or plume agate, which looks like it's filled with beautiful feather plumes,etc.
The colors and "scenes" in agate are endless. While agate is usually an inexpensive stone, some varieties or special stones with very unusual scenes or markings can be quite expensive and are used in high end jewelry, but rarely for a weddingg or an engagement rings.
Agate is found in: the USA, Brazil, Mexico, Egypt, Congo, Italy, India, Nepal and Germany.
|Agate - Main Characteristics|
|Hardness (Mohs Scale)||Seven (7)|
|Composition||Varies, mostly Silica|
|Crystal Habit||Cryptocrystalline quartz|
|Color/Spectrum||White, black, green, brown, blue, red, etc.|
|Atomic (Crystal )Structure ||Cryptocrystalline silica|
|Index of Refraction||Milky - Transparent|
|Uses||Jewelry, decorative and ornamental art, grinding machinery|