Characteristics of Agate:

Chemical Name: Silicon dioxide

Formula: SiO2

Colors: All colors

Structure: Trigonal

Hardness: 7

Specific Gravity: 2.6

Refractive Index: 1.53-1.54

Lustre: Vitreous

Streak: White

Locations: Worldwide, notably Brazil, Botswana, South Africa, Egypt, Mexico, China, and Scotland, fire agate only northern Mexico and southwestern USA

 

What is Agate? 

The microcrystalline, compact variety of quartz, agate is a common, semiprecious chalcedony. Agate is mostly characterized by color bands in a concentric form, and less often by moss-like inclusions, when it is called moss agate. Other names, such as fire, or Brazilian, often precede the word agate and these can describe the locality where they are found, or denote a particular appearance or coloration. Agates are almost always cut en cabochon, carved, or used as bead or ornaments.

 

In the Middle Age, wearing agate was thought to cure insomnia and ensure sweet dreams.

 

Types of Agate

Fire agate is an unusual variety that has iridescent rainbow colors, with brown to honey-colored base material. Cutting is a meticulous process, removing only enough stone to reveal the ‘fire’.

 

Fortification agate is a general term for banded agate with angularly arranged bands. Brazilian agate is a fortification agate with banding in angled concentric circles.

 

Mexican lace agate – called “crazy-lace” is a multicolored fortification agate with convoluted layering.