Tuesday, June 21, 2011

Calsilica... Mysterious Wonder Stone or Man-Made Rainbow?

Calsilica... the debate goes on!
Mysterious Wonder Stone or Man-Made rainbow?

Ever since Calsilica was introduced to the international jewellery scene back in 2002, fashion gurus and jewellery artists alike have debated the origins and authenticy of Calsilica.

With solid stripes of vibrant colours this 'stone' looks like a veritable rainbow. Reds, blacks, browns, black, greens, mustard yellows and turquoise mixed with orange, blues and salmon colours - Calsilica is a visual feast and wonderous to look at.  But the question is: "Is it real?" 

When I saw my first piece of rainbow calsilica (purchased from Cabbing Rough) I couldn't help but question it's authenticity. 

Certainly a beautiful cabochon with endless design possibilities...  But, is it real?

Later on, I came across some eye-catching candy on the fancy bead wall of my local wholesaler Rainbow Minerals.  Eyeing up the bright uniform bands of colour, there was no way I could believe they were natural.  So, I decided to put on my detective cap and dig into the story of this mysterious 'stone'....

Initially it was claimed that Calsilica originated from a mine located in the Mexican state of Chihuahua. 

Nevertheless, geologists were apparently denied access to the min in Chihuahua with the argument that permission of geologists into the mine would lead to over-exploitation.  Hmmm, sounds fishy! 

Since then, there have been claims of calsilica deposits in China, Brazil, even the Middle East and so the debate continues...

Back in 2002 this Mexican wonder stone caused quite a stir when the Swiss Gemological Institute picked up a few specimens at a mineral show in France.   After testing the slabs, they discovered both polymer and a paraffin-like substance as well as blue and yellow pigments that matched synthetic pigments.   While the supplier claimed the slabs were treated with paraffin and resin in order to make the stone more resilient, the Swiss Gemological Insititute had their doubts!  A report was issued concluding that the samples contained pulverized carbonate rock mixed with pigments and stabilized with a polymer (Winter 2002, Vol. 8, Gems & Gemology).

Some claim that Rainbow Calsilica was formed from silicate lying in the bottom of a cutting well for an old tile factory in Mexico which eventually solidified into the slabs we now consider calsilica.  Others say its a synthetic mixture of calcite, plastic and artificial colouring pigments.  Still others claim that untreated slabs of calsilica were found to be authentic...  And then there are others who - seeing similarity with Fordite speciments - believe calsilica to be made from paint chips collected from old automobile plants. 

In the end, the debate continues.  Personally, having a strand of drop beads, coin beads and a lovely little cabochon at my disposal, I tend to side with the Swiss Geological Institute on this one. 

Nevertheless, it remains a beautiful 'stone' in many respects.  Bright, colourful and vibrant, the controversy only adds to the attraction and mystique of rainbow calsilica while making for a great conversation starter ;)


- Tara, Treasure Trunk Designs

Watch TTD live:


 Become a TTD facebook fan at:


 Check out  

Treasure Trunk Lifestyles!


  1. its 100% man made its layer on layer of car Paint!!!!!!!!!

    1. Your wrong according to the Dr in Sweden and Arizona State University Geology Department and the originating owner of the original/initial sample from Kingman there is no plastic or paraffin, resin only and natural earth stone. But believe what you want it still sells for a premium.

  2. Totally agreed! I only wish the were consistently marketed as such. Either way, fun to work with and makes for interesting discussions :) Thanks for posting Yordi!

  3. great info,Just finished a gourd American Indain mask using Calsilica in the head dress.It's a looker!!!


Share your thoughts by commenting!