Genuine Fire Agate is gorgeous, rare and expensive, and in the last few years there have been a lot of crystals on the market claiming to be Fire Agate. So how do you know what's real and what's mislabelled?
Once you see a piece of genuine Fire Agate, it becomes very easy to tell the difference from the Carnelian often sold as Fire Agate - if you look on Etsy over half the results on a Fire Agate search will bring up mislabelled Carnelian in various forms.
This is what genuine Fire Agate looks like:
Real Fire Agate can be found in the southwestern USA in California/Arizona, and Mexico. It is technically a Chalcedony rather than an Agate as well, as it is not banded as Agates technically should be, but the name has stuck! The rainbow colours are created from many layers on top of each other that let light in which then diffracts. Fire Agates are usually found as bubbly rainbow masses with incredible rainbow shimmer when polished.
If you google Fire Agate, you will get a lot of results that look like these:
Many of these will be Carnelian that has been heat treated to give it the crackle effect, in a similar way to crackle quartz. It also goes by various other names, such as Snakeskin Carnelian, Fire Carnelian, and Snakeskin Fire Agate. These are much cheaper than true Fire Agate, which is usually sold as Cabochons due to the small nature of the pieces.
Seeing the two side by side, it is much easier to tell the difference - the heated Carnelian will be in varying shades of red/orange/yellow with no iridescence, whereas true Fire Agate will display various shades of iridescent colours - most commonly reds, but also rare shades of greens, blues and purples!