Jul 31, 2015
seen from China
seen from Türkiye
seen from Poland
seen from Netherlands
seen from China
seen from Poland
seen from South Korea
seen from Netherlands
seen from Türkiye
seen from Poland
seen from China
seen from Germany
seen from Saudi Arabia
seen from Poland
seen from Poland
seen from Türkiye
seen from Germany
seen from Japan
seen from Malaysia
seen from Singapore
Hutchinsonite is a rare sulphosalt mineral with the chemical formula (Ti,Pb)2As5S9. It is one of a few thallium minerals, all of which are rare. It is black or dark red/pink in colour and is subtranslucent to opaque with a submetallic lustre. Its crystals are acicular (needle-like) in habit or prismatic, resemblining tourmaline crystals. It has a hardness of 1.5-2 and a red streak.
Thallium is a soft, malleable metal with applications in electronics, pharmaceuticals, and glass manufacturing. It, along with arsenic, gained notority as a poison, and compounds of both elements were historically used as murder weapons, although arsenic is more well-known for this.
Sources:
Wikipedia (For thallium)
Webmineral
Image 1: 7mm hutchinsonite crystal on quartz from Quiruvilca Mine, Peru. Image by Didier Descouens, under a creative commons license on Wikimedia commons. Image 2 and 3: Hutchinsonite from the same locality as 1, from irocks.com. Sources here and here, respectively.