Dalmatian Stone from Chihuahua
Large Dalmatian Stone also known as Dalmatian Jasper.
Dalmatian Jasper is a trade name which came about because of the stone's spotted appearance. Ironically, most of the world's supply comes from the state of Chihuahua in Mexico.
Trade names are widely used to popularise certain minerals, but they can often be misleading about the material's chemical composition.
Tests carried out on Dalmatian Jasper revealed it's an alkali feldspar granite. The correct name for this material is Perthite, after the city of Perth (Ontario, Canada) which is close to where it was discovered.
Although often reported to be tourmaline, the distinctive spots are arfvedsonite. This rare mineral was named after the Swedish chemist Johan August Arfwedson, who discovered it.
