Tiffany Stone from Western Utah USA
Tiffany stone is a rare type of rock made up of a number of different minerals hence is not a mineral in its own right. To be precise it's a mineralized nodule that can only be found in one location in Western Utah (USA). The nodules were once impregnated by ground water rich in natural minerals including quartz and fluorite and along with manganese oxide, it's these minerals which give tiffany stone its striking colour.
Tiffany stone is a popular decorative material sometimes referred to as bertrandite which is not accurate. Bertrandite which is a primary source of beryllium is a mineral in its own right and the very reason why the vast majority of tiffany stone is crushed up. Beryllium is a highly sought after chemical element so by crushing tiffany stone the relatively small amount of bertrandite that's present can be extracted.
Being graded 4 on Mohs scale of mineral hardness means that tiffany stone is a relatively soft material so must be handled carefully. It's widely used for cabochons because its colour and striking markings make it ideal for use in items of jewellery.
The Name Tiffany Stone
Despite extensive research we cannot find any factual information to explain how the name tiffany stone came about. Although many articles online state the name is linked to tiffany glass, there's little to no evidence to support that.
Tiffany stone is also sometimes called ice cream opal or opalized fluorite, the latter from a geological perspective is a more precise description of what the stone actually is.
Tiffany stone is a trade name which is likely to have come about by chance when it was casually named soon after being discovered. As it gained popularity the name is likely to have stuck and once photos and articles began appearing online it would have been extremely difficult and far too late to re-name it.
The primary deposit in Utah where tiffany stone is found is no longer open or being mined so existing stocks are depleting rapidly.
The photo at the top of this article which is courtesy of James St. John is clickable and redirects to the original full size image.