Mineralpedia Details for Mimetite

Named after the Greek word mimitis, meaning “imitator,” as Mimetite often imitates or mimics pyromorphite. Mimetite has many localities worldwide, however some well crystallized material comes from localities in Germany, the Czech Republic, England, Scotland, Namibia, Iran, the USA, Mexico, Australia, and Thailand. Widespread and found as a secondary mineral in the oxidation zone of lead-bearing ore deposits. Crystals ae millimetric to centimetrix in size, usually forming stout, hexagonal crystals with pinacoids but often with pyramidal terminations, often barrel-shaped to globular. Can be acicular in radial sprays. Colors are typically yellow to deep yellow, orange to bright orange and burnt orange, can be green.

Ref. Minerals and their Localities, Bernard, J.H. and Hyršl, J. (2004)
Encyclopedia of Mineralogy, 1st edition Roberts & Rapp (1974).
Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/mimetite.pdf

Formula

Pb₅(AsO₄)₃Cl 

Crystal System

Hexagonal 

Crystal Habit

Reniform, Globular, Prismatic 

Cleavage

Imperfect, None, None 

Luster

Adamantine - Resinous 

Color

white, yellow, orange, brown, red 

Streak

white 

Class

Hexagonal - Dipyramidal 

Fracture

Brittle - Conchoidal 

Hardness

3.5-4 

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Deep yellow crystal groups to 8mm and bright yellow and green, acicular Mimetite crystals to 1mm covering the large cavit with Wulfenite.

Hony colored hexagonal crystals to 4mm.

Mimetite from San Pedro Corralitos is somewhat of the standard for the species. It is highly coveted for its candy-like yellow botryoidal crystals. This specimen has a shimmer or chatoyancy that catches the light when turned. The single botryoids are about 3-5mm across.

Light green Mimetite crystals scattered on the upper surface of a quartz-vein matrix. The Mimetite crystals are the classic barrel-shaped, curved crystals and typically measure about 1mm. All of the crystals grade to colors of yellow, green, cream or buff and show a brilliant subadamantine luster.

Partial sixling Cerussite crystals to 4-5mm completely overtaken by light yellow almost white Mimetite crystals. 

 The large crystals are pseudomorphs of Cerussite replaced by Mimetite to 1.2cm.

Light yellow, stubby, hexagonal crystals of Mimetite encrusting and replacing Cerussite sixling twins to 4mm.

Unsual pseudomorphs of yellowish to greenish yellow minute, hexagonal Mimetite crystals replacing twinned Cerussite crystals to 7mm.

Burnt orange and yellow-green "balls" of Mimetite variety "Campylite" to 5mm.

Fiery orange fibrous crystals to 2mm with translucent, tabular Wulfenite crystals to 2mm.

1mm acicular Mimetite sprays associated with Wulfenite.

Yellow acicular crystals to 3mm.

Honey yellow "jackstraw" like bunch of prismatic crystals tapering to a point.

Honey yellow perfectly translucent and gemmy Mimetite crystals to 1.3cm showing pyramidal and pinacoidal terminations. This specimen is from the famed "Gem Pocket" at Tsumeb.

Yellow, barrel-shaped or rice-shaped crystals to 3mm in a healthy dose across face. It's an older specimen, but I do not have an older label.

Open fractures filled with yellow fibrous crystals to 2mm.

Bright yellow tuft-like crystal clusters to 2mm on limonitic matrix with minor Anglesite.

Yellow hexagonal crystals to 7mm on Quartz matrix. 

Intense deep orange prismatic crystals of Mimetite to 4mm. 

Yellow to orange fibrous looking Mimetite.

Botryoidal Mimetite with weird tubular habit crystals.