Chalcosiderite
Current inventory:  0 gems
 

  
Chalcosiderite was named by Johann Christoph Ullmann in 1814 from the Greek words for copper and iron, for those elements in the mineral’s composition.

Discovered in 1814;   IMA status:  Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

CuFe²⁺₆(PO₄)₄(OH)₈ • 4(H₂O)

Hydrated Copper Iron Phosphate Hydroxide

Molecular Weight:

986.63 gm

Composition:

Iron

33.96 %

Fe

43.69 %

FeO

Copper

6.44 %

Cu

8.06 %

CuO

Phosphorus

12.56 %

P

28.77 %

P₂O₅

Hydrogen

1.63 %

H

14.61 %

H₂O

Oxygen

45.41 %

O

100.00 %

95.14 %

= TOTAL OXIDE

Classification

Mineral Classification:

Phosphates

Strunz 8th Ed. ID:

7/D.15-60

Nickel-Strunz 10th Ed. ID:

8.DD.15

8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H₂O
D : With only medium-sized cations, (OH, etc.):RO₄= 2:1

Related to:

Turquoise Group. Chalcosiderite-Turquoise Series.

Members of Group:

Turquoise Group: Aheylite, Chalcosiderite, Faustite, Planerite, Turquoise

Varieties:

Alumo-chalcosiderite

Synonyms:

None

Crystal Data

Crystallography:

Triclinic - Pinacoidal

Crystal Habit:

Crystals short prismatic, with a number of forms noted, typically in sheafs, to 3 mm; and in crusts.

Twinning:

None

Physical Properties

Cleavage:

Perfect on {001}, good on {010}

Fracture:

Irregular/Uneven

Tenacity:

Brittle

Moh's Hardness:

4.5

Density:

3.22 (g/cm³)

Luminescence:

Not Fluorescent

Radioactivity:

Not Radioactive

Optical Properties

Color:

Dark green, apple-green, pale green

Transparency:

Transparent to Translucent, Opaque

Luster:

Vitreous

Refractive Index:

1.775 - 1.844  Biaxial ( - ) 

Birefringence:

0.0690

Dispersion:

Very strong, crossed; r > v

Pleochroism:

Weak; X = colorless; Z = pale green

Occurances

Geological Setting:

A rare mineral in the oxidized zone of some hydrothermal mineral deposits.

Common Associations:

Dufrénite, Goethite (West Phoenix mine, Cornwall, England); Dufrénite, Cyrilovite, Leucophosphite (Gunheath china clay pit, Cornwall, England); Sampleite, Libethenite, Crandallite, Cyrilovite, Pseudomalachite, Saléeite, Torbernite, Ulrichite (Lake Boga quarry, Australia).

Common Impurities:

Al

Type Locality:

Phoenix United Mine, Minions, Linkinhorne, Liskeard District, Cornwall, England, UK

Year Discovered:

1814

View mineral photos:

Chalcosiderite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Chalcosiderite is a rare copper phosphate mineral found in the oxidized zone of some hydrothermal mineral deposits. It is a member of the Turquoise Group of minerals that includes Chalcosiderite , Faustite, Planerite and Turquoise.

Chalcosiderite's colors are bright, dark green, apple-green or pale green. Chalcosiderite is in a solid solution series with Turquoise. Chalcosiderite and Turquoise have the same structure, just slightly different chemistries. Turquoise is the aluminum rich end member of the series and Chalcosiderite is the iron rich end member. It's Chalcosiderite's iron content that produces its usually darker color as opposed to Turquoise's lighter blue-green. Chalcosiderite is rarely available on the gem market but cabochons are occassionally available. Material from the Lander Ranch mine near Tenabo, Lander County, Nevada makes for very attractive, pale green cabochons.

Distribution: In England, from the West Phoenix United mines, Linkinhorne, and the Gunheath china clay pit, St. Austell, Cornwall. In Germany, at Schneckenstein, and in the Tannenberg mine, Mühlleithen, Saxony; from Hagendorf, Bavaria. From the Miguel Vacas mine, Estremoz, Portugal. At Les Montmins, Auvergne, France. In the USA, from the Lander Ranch mine near Tenabo, Lander County, Nevada; from the Cole and Shattuck mines, Bisbee, Cochise County, Arizona; in the Tyrone mine, Santa Rita, Grant County, New Mexico; at the Mohawk mine, Clark Mountains, San Bernardino County, California; from the King turquoise mine, Conejos County, Colorado. In Australia, in the Lake Boga granite quarry, near Swan Hill, Victoria, and the Spring Creek mine, near Wilmington, South Australia.
 

  
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