Ojuela Mine, Mapimí, Mun. de Mapimí, Durango, Mexico © MJO

Chemical Formula: Zn2(AsO4)(OH)
Locality: Ojuela mine, Mapimi, Durango, Mexico
Name Origin: Named as the dimorph of adamite.

Paradamite is dimorphous with a famous arsenic mineral, namely adamite. Dimorphous means that the two minerals have the same formula, but different structures (di means two; morphous means shape). Paradamite’s different structure produces only slight differences in physical properties. Most obvious however is the difference in crystal forms. Adamite’s typical form is wedge shaped prismatic crystals with diamond-shaped cross-sections. Paradamite’s form is more tabular in character and very different from adamite’s. Although their names are similar and their chemistry is the same; paradamite and adamite are absolutely distinct minerals.

Optical properties

Optical and misc. Properties:Transparent
Refractive Index: from 1,72 to 1,78
Axial angle 2V : 50°

Physical properties

Color : pale yellow
Luster: vitreous.
Transparency: Crystals are transparent to translucent.
Crystal System: triclinic; bar 1.
Crystal Habits include rounded tabular crystals, usually aggregated.
Cleavage: perfect.
Fracture: uneven.
Hardness: 3.5.
Specific Gravity: approximately 4.5 – 4.6 (heavy for translucent minerals)
Streak: white.


Paradamite Mina Ojuela, Mapimi, Durango,Mexico Miniature, 4.4 x 3.3 x 2.0 cm “Courtesy of Rob Lavinsky, The Arkenstone,”
Paradamite Location: Ojuela mine, Mapimi, Druango, Mexico. Copyright: © Lou Perloff / Photo Atlas of Minerals
Paradamite Locality: Ojuela Mine, Mapimí, Mun. de Mapimí, Durango, Mexico Photo Copyright © Marcus J. Origlieri
Paradamite Mina Ojuela, Mapimi, Durango, Mexico Miniature, 4.9 x 3.8 x 3.8 cm “Courtesy of Rob Lavinsky, The Arkenstone,”