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How to Recognize Fire Agate

Fire agate is a type of chalcedony, or quartz, prized for its iridescent rainbow of colors that seem to glow from deep within the stone. Fire agate forms in layers when hot water containing colloidal silica and iron oxide seeps into rock seams, and then cools. The iron oxide gives fire agate its unique, firey quality that some people liken to opals.

Things You'll Need

Hammer
Chisel
Stiff brush
Goggles or safety glasses
Bucket
Spray bottle of water

Instructions

- 1
  Find a good source for fire agates. There are dig-for-fee commercial mines in southern Arizona. You can also look for fire agates in California, around the Colorado River and parts of Mexico.
- 2
  Be prepared to do some hard-rock mining. You might have to cover a large area before you find a seam or pocket of potential fire agates.
- 3
  Use your hammer and chisel to break off pieces of rock. Fire agate is usually surrounded by dark brown quartz.
- 4
  
  Fire agate in the rough can be hard to spot. Instead of regular bands of color and crystals found in geodes and quartz, fire agates often have a surface marked with irregular bubbles, bumps or swirls of color.
- 5
  You might have to break the stone in half to see the fire agate. Spraying the stone with water can help highlight any color. Look for the iridescent reds, greens, yellows or blues that are characteristic of fire agate.
- 6
  If you do not want to dig, look around in tailings at mine sites. A piece of fire agate may have been left behind.
- 7
  Polish the stone with care. Fire agate is a layered stone, and polishing one layer too deep will destroy the colorful effect.

Rocks & Minerals