Mimetite

Mimetite Hat Yai, Hat Yai District, Songkhla Province, Thailand Specimen weight:82 gr. Crystal size:to 0,75 cm Overall size:6,5 x 5 x 2,2 cm © minservice

Chemical Formula: Pb5(AsO4)3Cl
Locality: Treue Freundschaft Mine, Johanngeorgenstadt, Erzgebirge, Saxony, Germany.
Name Origin: From the Greek mimethes – “imitator” , because of its resemblance to pyromorphite.

Mimetite, whose name derives from the Greek Μιμητής mimetes, meaning “imitator”, is a lead arsenate chloride mineral (Pb5(AsO4)3Cl) which forms as a secondary mineral in lead deposits, usually by the oxidation of galena and arsenopyrite. The name is a reference to mimetite’s resemblance to the mineral pyromorphite. This resemblance is not coincidental, as mimetite forms a mineral series with pyromorphite (Pb5(PO4)3Cl) and with vanadinite (Pb5(VO4)3Cl). Notable occurrences are Mapimi, Durango, Mexico and Tsumeb, Namibia.

History

Discovery date : 1832

Optical properties

Optical and misc. Properties : Subtransparent to translucent

Physical Properties

Cleavage: {1011} Imperfect
Color:     White, Yellow, Orange, Brown, Red.
Density: 7.1 – 7.24, Average = 7.17
Diaphaneity: Subtransparent to translucent
Fracture: Brittle – Conchoidal – Very brittle fracture producing small, conchoidal fragments.
Hardness: 3.5-4 – Copper Penny-Fluorite
Luminescence:     Fluorescent, Short UV=orange, Long UV=orange.
Luster: Adamantine – Resinous
Streak: white

Photos :

Mimetite Ojuela Mine, Mapimi, Durango, Mexico Small Cabinet, 8.5 x 4.5 x 2.7 cm © irocks
Mimetite Bilbao Mine, La Blanca, Ojo Caliente, Zacatecas, Mexico ex. Consie & Dalton Prince Small Cabinet, 7 x 5.5 x 4.5 cm © irocks
Mimetite Grube Haus Baden, Sehringen, Baden-Württemberg, Germany Specimen weight:118 gr. Crystal size:to 0,4 cm Overall size: 70mm x 42 mm x 33 mm © minservice
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