Is a zinc carbonate with formula ZnCO3. Hardness 4-4.5.
It is found in various part of the world, from Namibia to Mexico and China.
Is one of the most important ore for the extraction of Zinc and can be found in various colors.
Here we have a Cadmium yellow variety quite rare coming from Masua ( Ma-Sua) area, near Cagliari, Sardinia, Italy. This area is near the famous Monteponi mine, closed since 40 years ago, produced beautiful led and zinc minerals; this material were obtain from an old collections and facetted into gems. Only few stones are available for the collectors and amateurs.