Mimetite - Encyclopedia

    Class : Phosphates, arsenates, vanadates
    Subclass : Anhydrous arsenates
    Crystal system : Hexagonal
    Chemistry : Pb5(AsO4)3Cl
    Rarity : Quite common

Mimetite belongs to the apatite group and is the arsenic pole of the mimetite-pyromorphite-vanadinite series. Very similar in appearance to the pyromorphite, it is from this characteristic that it owes its name : from the Greek mimetês (imitator). It is much rarer than the latter. Like pyromorphite, mimetite occurs in the oxidation zones of lead deposits. When pure, mimetite is colorless to yellowish with almost adamantine luster. It is a very rare case, the crystals are much more commonly yellow, yellow-orange to orange-red with resinous brightness, sometimes green. The crystals are prismatic surmounted by a pyramid, in hexagonal barrels with curved edges (campylite facies) or in reniform to globular masses. It is an ancillary ore of lead, these crystals are sought after by  mineral collectors.

Mimetite balls from Haus Baden Mine, Germany
Mimetite from Hat Yai District, Songkhla Province, Thailand
Mimetite from Potosi Mine, Santa Eulalia, Chihuahua, Mexico
Mimetite from Pingtouling Mine, Guangdong, China

Mimetite in the World

The best prismatic specimens come from Tsumeb (Namibia) where yellow crystals exceptionally reach 6 cm. The Saxon community of Johanngeorgenstadt (Germany) is home to beautiful yellow crystals up to 2 cm high in the clinomimetite variety. The Bonney mine in Australia supplied similar 15 mm gemmy ones. Beautiful yellow prismatic crystals sometimes skeletal more than 2 cm are also from the Pingtouling mine in China (main photo), but also from Hat Yai District in Thailand (centimeter). The campylite facies of mimetite is particularly well represented at the Dry Gill mine at Caldbeck Fells (Cumberland, England), from which bright yellow-orange centimetric crystals originate. Finally, very beautiful globular yellow-orange are known in the Mexican mines of El Potosi and Ojo Caliente.

Mimetite in France

In France, mimetite is present in Molérats (Saône-et-Loire), Lantignié (Rhône) where it is found associated with wulfenite, barite and fluorite (photo right). It is also reported in millimetric transparent crystals in the old mine of Cap Garonne (Var). According to recent analyzes, however, it seems that the large yellow crystals with campylite facies of the Farges Mine in Corrèze are actually only pyromorphites.

Twinning and special forms

There is a very rare twin on {11-22}.

Fakes and scams

No fake for this mineral species, but can sometimes be easily confused with pyromorphite, indeed without chemical analysis, it is sometimes impossible to tell the difference.



Hardness : 3.5 to 4
Density : 7.24
Fracture : Irregular to subconchoidal
Trace : White


TP : Transparent to translucent
IR : 2.128 to 2.147
Birefringence : 0.019
Optical character : Uniaxial -
Pleochroism : Weak
Fluorescence : Yellow to orange (rare)


Solubility : Nitric acid and potash

Magnetism : None
Radioactivity : None