VivianiteThese Vivianite crystals have, without question, the best luster and often gemminess of any Vivianite specimens to date from this country, or virtually any other country. Another outstanding feature is the wonderful color contrast between the vivid emerald green of the Vivianite and the altered red sandstone matrix. These pieces have what I think is some of the best matrix for these crystals from Bolivia. It's not completely unstable like decomposing

which was supposed to be an intermediary species between Ferberite and Hubnerite

The piece features an excellent

translucent greenish-brown colored Siderite crystals and minor grey crystals of the rare sulfide

and top-notch both from the standpoint of excellence and associations

but it’s more than forgivable considering that there virtually every Ferberite from Tasna has some kind of imperfection

twinned Ferberite specimen from the famous Tasna mine in Bolivia

and not terribly attractive

Specimen # BOL711B73

white/colorless

There were only a handful of good specimens

The piece looks like it’s from the famous Contacto vein where some of the most important phosphate specimens were found at Siglo XX

which means that this specimen has at least SEVEN individual species on the same piece