Fire Agate
Information
Above: Cabochon cut fire agate and closeup of stone. Note stone is flat in spite of curved appearance.
What color is it?: I guess you could best describe it a the color of fire. Looking at a fire agate is much like looking down into the burning embers of a fire. Which is exactly how it got its name. If this sounds a little schmaltzy then you have never seen a really nice quality fire agate. Because once you have the above description will be the only one you will have too.
What is the story behind this gemstone?: This is a very unusual form of chalcedony or the quartz family, known as agates. This particular type is unlike anything else in the gemstone world because looking into a nice fire agate makes you feel like you are looking deep into a burning ember. (That's just the only way I know how to describe it)
Can I wear it everyday?: Yes it is very long wearing and tough.
Is it expensive?: Relatively inexpensive. About the same price as a nice piece of Lapis Lazuli in the finest quality.
Is it a birthstone?: No
What do I need to know before going shopping?: First, don't shop for fire agate on eBay. Or you might wind up with some mid-quality stones like I did with the one's on this page. Fire agate must be seen in person to be truly appreciated. Second, if you are buying it rough, spread a little spit on the stone to get a good idea of what it will look like polished (which is why these stone look a little wet, but just wait until we start testing cultured pearls). Beyond the above look in your independent jewelry stores who carry a lot of colored stones and will have a selection to offer. Every single fire agate on the planet will be a little bit different. So you will want to be able to choose from several to make sure you have one you really like.
General
Information
Source: Mexico and Brazil
Chemical: SiO2 (same as quartz)
Formation: Hydrothermal environment
Crystal System: None. Will occur in the botryoidal formation as seen in the two photos above.
Unusual Properties: Optical illusion of depth and play of color.
Gemological
Information
RI: 2.60 + -
Birefringence: None
Optic Character: U+
Specific Gravity: 2.64 + -
Hardness: 7
Transparency: Opaque
Special Identifying Properties and Tests: Optical property generally diagnostic. Should not be confused with opal due to SG and RI. And once you have seen it you will always know it.
Synthetics: None known at this time
Imitations: None known at this time