Rainbow Calsilica - Myth Or Reality?

When calsilica first appeared on the fashion jewelryseams of the volcanic rhyolite in the mine.
scene several years ago, it made quite a splash! WithCalsilica was thought to be a form of microcrystalline
its bright, vivid, and varied colors, it is not hard tocalcite, with various clay minerals as the bonding
understand why calsilica captured the imagination ofagents. Supposedly, the mine in Mexico would send out
jewelry designer as well as jewelry wearers alike.letters of authentication and photographs of the mine.
Calsilica earrings, silver pendants, rings, and other itemsNow there are rumors of a spectacular deposit of
were often the stars at gem and jewelry shows.natural calsilica in China. In 2003, the Swiss Gemological
So what is calsilica and where does it come from?Institute ( ) published a brief note on calsilica in one of
The general consensus is that calsilica is a man-madetheir newsletters. SSEF purchased two specimens at
amalgamation of various minerals and stonea mineral show in France in 2002. The seller produced
fragments that are held together with resin. Often, thephotographs of the mine in Mexico, along with a
powder and fragments are deposited under waterauthentication letter from a US laboratory stating that
and compressed to form cake. The cake is dried andthe materials were not man-made. They found that
infused with resin. Once the resin hardens, variesthe base white materials were indeed a calcite.
pieces are cut from the block, and then polished toHowever, they also found that man-made coloring
achieve the desired sheen. Since calsilica is man-madepigments within the specimens. More importantly, SSEF
there very well could be other processes used in itsfound that the particles were bonded together by a
manufacture.transparent soft, plastic-like material that was very
Although many claim that calsilica (or "rainbow calsilica"similar to paraffin wax.
as it is sometimes called), is a naturally occurringThe preponderance of the scientific evidence
material, there is little evidence to support this claim.therefore indicates that calsilica is a man-made
The most persistent claim (and it still persists today!)material. Nonetheless, good calsilica specimens are
was that calsilica was mined in Chihuahua, Mexico.pretty, and can be used to make attractive,
Calsilica was allegedly discovered in the veins orinexpensive fashion jewelry.