Click on a letter above to view the list of gems.  

Conichalcite
Current inventory:  0 gems
 

Chemistry:  CaCu(AsO4)(OH)
[Calcium Copper Arsenate Hydroxide]

Discovered in 1849;   IMA status: Valid (pre-IMA; Grandfathered).
Conichalcite is named from the Greek words konis for powder and chalkos for copper in allusion to its composition and appearance at times.

Classification

Mineral Classification:

Arsenates

Strunz 8th Ed. ID:

7/B.26-50

Nickel-Strunz 10th Ed. ID:

8.BH.35

8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H₂O
H : With medium-sized and large cations, (OH,etc.):RO₄ = 1:1

Related to:

Adelite - Descloizite Group. An end member in the Austinite - Conichalcite Series, the Cobaltaustinite - Conichalcite Series, the Concichalcite - Duftite Series and the Conichalcite - Tangëite Series.

Crystal Data

Crystallography:

Orthorhombic - Disphenoidal

Crystal Habit:

Rarely as euhedral crystals, equant to short prismatic along [010], to 3 mm, terminated by many forms, both left- and right-handed; typically in radial fibrous aggregates, as botryoidal to reniform crusts, massive.

Twinning:

Rare on [001]

Physical Properties

Cleavage:

None Observed

Fracture:

Irregular/Uneven

Tenacity:

Brittle

Hardness (Mohs):

4.5

Density:

4.33 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Other:

Easily soluble in HCl or HNO3

Optical Properties

Color:

Grass-Green, Yellowish Green, Pistachio-Green, Emerald-Green

Transparency:

Translucent

Luster:

Vitreous to somewhat Greasy

Refractive Index:

1.778 - 1.846  Biaxial ( + ); may be Biaxial ( - )

Birefringence:

0.0410 - 0.0460

Dispersion:

Strong (r > v ) to Moderate (r < v)

Pleochroism:

X = colorless to green; Y = pale greenish to yellow-green; Z = pale bluish to blue-green.

Occurances

Geological Setting:

An uncommon secondary mineral in the oxidized zone of copper deposits, typically an alteration product of enargite.

Common Associations:

Austinite, Azurite, Brochantite, Chenevixite, Clinoclase, Jarosite, Libethenite, Limonite, Malachite, Olivenite

Common Impurities:

Mg, P, V, Zn

Type Locality:

Hinojosa del Duque, Córdoba, Andalusia, Spain

Year Discovered:

1849

View mineral photos:

Conichalcite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Conichalcite is a rare copper arsenate mineral that is found in very striking shades of green. It is typically found as radial fibrous aggregates, botryoidal to reniform crusts or massive. Conichalcite is occassionally found mixed in with Calcite or Quartz. When this occurs, beautiful cabochons can be made. This occurrence is very rare.

There are many minor localities for Conichalcite but fine crystals are extremely rare. A couple possible sources of Conichalcite mixed in with Calcite or Quartz are Bisbee, Cochise County, Arizona and Tsumeb, Otjikoto Region, Namibia.
 

  
Conichalcite gems for sale:

We have not photographed our Conichalcite gems. Please check back soon.