Weissbergite & Parapierrotite

Description

Weissbergite has a hardness of 1½ and a specific gravity of 5.79, while Parapierrotite has a hardness of 2½ – 3 and a specific gravity of 5.07. Weissbergite was named after Byron G. Weissberg, a geologist and mineralogist with the Department of Scientific and Industrial Research of New Zealand, and and Parapierrotite was named for its close relation to Pierrotite, which was named after Roland Pierrot, a French mineralogist and Head of the Mineralogy Department and General Secretary of the National Geographical Service at BRGM (French Geological Survey).

Mindat cautions that both Weissbergite and Parapierrotite “contain thallium – always wash hands after handling. Avoid inhaling dust when handling or breaking. Never lick or ingest.” Parapierrotite is found in roughly 13 localities worldwide and Weissbergite is found in only 4 localities worldwide, both near hydrothermal deposits, and neither have been found yet in Colorado.

Parapierrotite was recognized to be found in Utah at the location from where this rock was originally found, as well an in Ontario, but Weissbergite is limited so far to Europe and Asia, and not yet listed on Mindat to be found in Utah, so that’s a little interesting…

As Thallium is as toxic as it is and as it’s used in such few ways, worldwide production of Thallium is nearly nonexistent, and limited to mostly extracting the trace amounts of it from Copper, Zinc, and Lead ores. For mineral and element collectors, that means an increased level of rarity and price. However, there are 92 known and named minerals containing Thallium, so not it’s fortunately not the rarest!

The minerals in this rock would make for a great addition to most any collection of mineral and element collector’s with Weissbergite’s 52% Thallium content and Parapierrotite’s 20%, but you probably shouldn’t bring this home otherwise. Although, keep an eye out for a rock like this on your next hike and you might be able to keep yourself safe and simultaneously make a new discovery!