496 - Mimetite and Limonite

ID	496
Mineral	Mimetite Limonite
Location	Ojuela Mine - Mapimi - Durango - Mexico
Fluorescence	LW-UV: close SW-UV: close
Mindat.org	View Mimetite information at mindat.org View Limonite information at mindat.org

ID	2714
Long ID	1:1:2714:0
Formula	`Pb₅(AsO₄)₃Cl`
IMA Status	0 1
Other Occurrences	It is a secondary mineral found in the oxidized zones of lead mineral deposits, and in other settings where lead and arsenic occur together.
Discovery Year	1832
Diapheny	Transparent,Translucent
Cleavage	In traces on {10_11}.
Tenacity	brittle
Colour	Pale-yellow, yellowish-brown, orangish-yellow, orangish-red, red, green, white, colorless; colourless or faintly tinted in transmitted light.
Hardness (min)	3.5
Hardness (max)	4.0
Lustre	Resinous to sub-adamantine
About the name	Named in 1835 by François Sulpice Beudant from the Greek μϊμητής for "imitator," in allusion to its resemblance to pyromorphite.
Streak	White
Crystal System	Hexagonal
Cleavage Type	Poor/Indistinct
Fracture type	Irregular/Uneven,Sub-Conchoidal
Morphology	Typically in simple prisms [0001], barrel-shaped, showing {10_10} and {1000}; also equant, rarely tabular {0001}, or pyramidal. Frequently as rounded, barrel-shaped forms; spindle-shaped, or with cavernous basal terminations; globular, stalactic, reniform and granular. Branching groups of prismatic crystals in sub-parallel position, tapering down to a point. Acicular at times.
Twinning	Very rarely on {11_22}.
UV	May fluoresce reddish yellow under SW and LW
key_elements	0 1 2
shortcode_ima	Mim
Group	Apatite Group

ID	2402
Long ID	1:1:2402:6
Description	Currently used as a field-term for unidentified massive hydroxides and oxides of iron, with no visible crystals, and a yellow-brown streak. 'Limonite' is most commonly the mineral species goethite, but can also consist of varying proportions of lepidoc...
Diapheny	Opaque
About the name	Named in 1813 by Johann Friedrich Ludwig Hausmann from the Greek λειμών for meadow alluding to its common occurrences in bogs.

Mimetite and Limonite