Wednesday, December 21, 2011


Arizona is known for its beautiful turquoise, as well as copper and copper-oxide minerals like chrysacolla, malachite, and azurite.  But also found here in Arizona, not far from Quartzsite, is another beautiful gemstone:  Fire Agate.  
There are only two known Fire Agate deposits in the entire world.  One covers an area  between the Sierra Madre Occidental and the Sierra Madre Oriental Mountain Ranges in Mexico about 100 miles north of Mexico City.  The other is the Sonoran Desert region in Arizona and California.  The closest sites to Quartzsite are the Opal Hill Mine, in Palo Verde, California, the Little Horn Mountains about 35 miles east of Quartzsite, and Oatman, AZ.  The Arizona and California Fire Agates have more brilliance, fire, and color than ones from Mexico.  

Fire Agate is a Chalcedony that was formed during the Tertiary Period, 24 to 36 MYA.  It is a cryptocrystalline silica with a hardness of 7, and is created when hot water saturated with colloidal silica and iron oxides is forced by volcanic activity up into cavities in the host rock.  The Chalcedony cools in botryoidal (bubble) forms.  The “Fire” is created when alternating layers of iron oxides and silica cover the mounds of Chalcedony, and then another layer of Chalcedony forms over top of these layers.  The iron oxide and silica layers refract light in a process called interference.  This causes the “Fire” we see in Fire Agates.

Fire Agate is sometimes considered to be an opal, but it’s not.  Fire Agate is a crystalline form of silica, not a hydrous one like opal, so it will not crack, craze, or fade.  It is a much more durable gemstone than opal, and very well suited for jewelry.  For the lapidarist, however, Fire Agate presents unusual challenges.  First of all, it is difficult to tell if a piece of rough contains fire or not, because the fire layers are hidden under layers of Chalcedony.   If it does, getting to the fire requires skill and exactness.  Layers of chalcedony must be ground away to expose the layers of fire, and it is very easy to remove too many layers, cut into the fire layers, and lose the fire altogether. 

Arizona Fire Agates are typically a brown to reddish brown color, with fire ranging from reds and yellows to blues and purples.   Some stones have fire containing all the colors of the rainbow.  Typically, Fire Agates are cut in freeform cabs to best enhance the natural shapes and patterns of fire within the stone.  

Arizona Fire Agates are available from Rocks In My Head, Space A37 in Rice Ranch, 605-376-8754,   We have cabs and rough, information on the local Fire Agate dig sites, and much,  much more.  


The Opal Hill Fire Agate Mine is the only Fire Agate mine in the world that is open to the public.  In addition to Fee Mining, the Opal Hill Mine offers full day and overnight tours to teach about the Fire Agates, show how to find them and what techniques work best for digging and collecting.  The fee for mining is $25.00 per person.  The prices for the tours vary.  

The Opal Hill Mine is located 20 miles south of Blythe, CA.  To get there from Quartzsite take I-10 west into California.  Take the Wiley’s Well Road exit and head South for about 11.5 miles, at that point you will see signs for the Opal Hill Mine. 

The mining at this site is hard rock mining.  To be properly prepared and enjoy your time at the Opal Hill Mine, bring plenty of water, food, sunscreen, and a hat- this is typical desert environment and there are no amenities.   You may also want to bring kneepads, safety glasses and work gloves to make your mining experience a little more comfortable.  The tools you will need are:  Rock Pick, Rock Hammer, Sledge Hammer, Chisel, and a Hand Broom.  Don’t forget to bring buckets or a backpack of some sort to carry out your treasures.  Be sure that the tools you bring are comfortable to use- you will be using them a lot.  You may even want to bring some sort of cushion to sit/lean/kneel on because the alternative is to sit/kneel/lean on rock.  

If you want to stay overnight, there are plenty of places in Blythe.  There is also a BLM camping area not too far from the mine.  


This is not a fee mining area.   This area is located on the north side of AZ route 191, between Safford and Clifton, about 18 miles north of Safford.  This is a BLM site, and the road beyond the registry sign is not maintained.   Travel trailers and passenger cars are not recommended.  There is no water, food, or gas available.  Pack in and pack out everything you need.  Just like the Opal Hill Mine, this is a hard rock mining area, and it is a harsh desert environment with no amenities.  As this is a BLM site, please care for the land so that this site will remain open for digging.   Please pack out all trash and garbage, fill in holes, and be careful with fire if you camp there.   Please be sure to leave this area beautiful for others and future generations to enjoy. 

We have Arizona Fire Agates for sale in the store at RocksInMyHead, Rice Ranch A37, Quartzsite, AZ- and also for sale on our website We have rough from the Opal Hill Mine, and also pre-forms and cabochons.

Creative Commons License
Fire In The Desert- Arizona Fire Agates by Jenn Jedidiah Free & RocksInMyHead is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at

Here is a video about the Opal Hill Mine.   For more videos about rockhounding, prospecting, rock cutting and polishing, and other cool stuff visit our YouTube Channel!

Also here is a RockHounding Book that has the Opal Hill Mine in it:

  BUY IT NOW:   Rockhounding California

and another recommended read for Fire Agate and other RockHounding sites in the Southwest:

and a Great all-around Rockhounding Book:

BUY IT NOW:      The Rockhound's Handbook


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