Chalcanthite
Current inventory:  0 gems
 

  
Chalcanthite is named from an older Latin name, chalcanthum, for flowers of copper. Chalcanthum is from the Greek chalkos, for copper and anthos, for flower.

Discovered in 1853;   IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

CuSO₄ · 5H₂O

Hydrated Copper Sulfate

Molecular Weight:

249.69 gm

Composition:

Copper

25.45 %

Cu

31.86 %

CuO

Hydrogen

4.04 %

H

36.08 %

H₂O

Sulfur

12.84 %

S

32.07 %

SO₃

Oxygen

57.67 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Sulfates

Strunz 8th Ed. ID:

6/C.04-40

Nickel-Strunz 10th Ed. ID:

7.CB.20

7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H₂O
B : With only medium-sized cations

Related to:

Chalcanthite Group. Copper analog of Melanterite.

Members of Group:

Chalcanthite Group: Chalcanthite, Jôkokuite, Pentahydrite, Siderotil

Varieties:

Phillipite

Synonyms:

Blue Stone, Blue Vitriol, Chalkanthite, Copper Vitriol, Cyanosite, Cyprian Vitriol, Suphate of Copper

Crystal Data

Crystallography:

Triclinic - Pinacoidal

Crystal Habit:

Crystal short prismatic {001} or less commonly tabular {111}. Natural crystals rather rare. Commonly found as stalactic material, massive, granular filling veins (cross-fiber veinlets) and as crusts.

Twinning:

Rarely as cruciform intergrowths with {010} common between individuals.

Physical Properties

Cleavage:

Imperfect on {110}, Indistinct on {111}; and, {110} in traces

Fracture:

Conchoidal

Tenacity:

Brittle

Moh's Hardness:

2.5

Density:

2.286 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Other:

Soluble in water, dehydrates in dry air.

Health Warning:

CAUTION: Poisonous! Copper sulfate solutions are poisonous. Do not lick or ingest. Do not touch with bare hands or wash hands immediately after handling!

Optical Properties

Color:

Green, Green Blue, light Blue, or dark Blue; Colorless to pale Blue in transmitted light

Transparency:

Translucent to Transparent

Luster:

Vitreous to Resinous

Refractive Index:

1.516 - 1.546  Biaxial ( - )

Birefringence:

0.0300

Dispersion:

r < v

Pleochroism:

None

Occurances

Geological Setting:

A secondary mineral in the oxidized portions of copper sulfide deposits, commonly of post-mining formation, forming on mine walls and by the action of acidic surface waters on copper veins; rarely as a fumarolic deposit.

Common Associations:

Melanterite, Fibroferrite, Rhomboclase, Epsomite, Goslarite, Pickeringite, Retgersite, Morenosite, Brochantite, Gypsum

Common Impurities:

Fe, Mg, Co

Type Locality:

Chuquicamata Mine, Chuquicamata District, Calama, El Loa Province, Antofagasta Region, Chile

Year Discovered:

1853

View mineral photos:

Chalcanthite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Chalcanthite is a water-soluble copper sulphate mineral that forms beautiful blue fibrous crystals. It is the copper analog of Melanterite. Chalcanthite is a hydrated copper sulphate mineral formed after the decomposition of other copper minerals due to the action of surface waters. It is often found in mines as a post-mining formation on mine walls as encrustations or stalactites.

Natural gem-quality crystals are quite rare so gems are mostly faceted from lab-grown material. These gems have one of the most intense, saturated bright blue colors availble for gems. Care must be taken to store gems or specimens in a sealed container with a desiccant to keep them dry since Chalcanthite can slowly absorb moisture from the air then lose it again. Over time, this cycle can cause a beautiful gem or mineral specimen to be reduced to a pile of blue dust.

Deposits of Chalcanthite are widespread; commercial deposits may occur in arid regions. From the Island of Cyprus. On Vesuvius, Campania, Italy. From Rammelsberg and Goslar, Harz Mountains, Germany. Abundant at Rio Tinto, Huelva, Spain. In Chile, from Chuquicamata, at Quetena, near Calama, and Copaquire, Antofagasta. In the USA, in Arizona, at the United Verde mine, Yavapai County, and in the Clifton-Morenci district, Greenlee County; from the Blue Bird mine, Fierro-Hanover district, Grant County, New Mexico; commercial amounts in the Bluestone mine, Yerington district, Lyon County, Nevada; at Butte, Silver Bow County, Montana; from Ducktown, Polk County, Tennessee.
 

  
Chalcanthite gems for sale:

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