Agate

Agate

The name is derived from the river Achates in southwestern Sicily where this gem occurs

Data:

Formula: SiO2
Color: Colorless, white, gray, red, any color due to embedded minerals
Multicolored copy not unusual
Gloss: Wash gloss
Hardness: 6½ - 7
Specific weight: 2.6
Transparency: Translucent / translucent to opaque

Agate is the aligned variety of Micro Crystalline Quartz: Chalcedony

Two characteristic types of stripes can be distinguished in Agates.

Wallline Banding:

The individual stripes run perpendicular to the orientation and growth direction of the chalcedony fibers.

As the chalcedony fibers grow from the walls to the interior of a cavity, a concentric, onion-like pattern develops.

Horizontal Banding:

This is also called Uruguay-type banding. This type is less common and consists of fine, irregularly distributed layers of small chalcedony spherulites and sometimes quartz crystals that precipitate in the cavity.

When the difference in transparency or color between the layers is pronounced, agates with horizontal stripes can be used for cutting cameos and engravings.

The Agate group includes among others: Chalcedony, and the various variants of Agate such as ,, Blue Lace, Tree, Botswana Carnelian, Moss, Red, Turitella, Fire, Water Agate. The names were created by the location, color, bands, drawing or inclusions of the Agate.

If in stock you will find below my collection of Raw Gemstones in this group.

Are you looking for cut Gemstones from the Agate Group? Look at AGAATGROUP