Woodhouseite
Current inventory:  0 gems
 

  
Woodhouseite is named after Professor Charles Douglas Woodhouse (1888-1975), American Mineralogist and mineral collector, University of California, Santa Barbara, California, USA.

Discovered in 1937; IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

CaAl₃(PO₄)(SO₄)(OH)₆

Calcium Aluminum Phosphate Sulfate Hydroxide

Molecular Weight:

414.10 gm

Composition:

Calcium

9.68 %

Ca

13.54 %

CaO

Aluminum

19.55 %

Al

36.93 %

Al₂O₃

Phosphorus

7.48 %

P

17.14 %

P₂O₅

Hydrogen

1.46 %

H

13.05 %

H₂O

Sulfur

7.74 %

S

19.33 %

SO₃

Oxygen

54.09 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Phosphates

Strunz 8th Ed. ID:

7/B.35-20

Nickel-Strunz 10th Ed. ID:

8.BL.05

8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H₂O
L : With medium-sized and large cations, (OH, etc.):RO₄ = 3:1

Related to:

Beudantite Group. Alunite Supergroup. The Ca analogue of Svanbergite.

Members of Group:

Beudantite Group: Beudantite, Corkite, Gallobeudantite, Hidalgoite, Hinsdalite, Kemmlitzite, Svanbergite, Weilerite, Woodhouseite 

Varieties:

None

Synonyms:

ICSD 100137,  Kehoeite, PDF 37-469

Crystal Data

Crystallography:

Trigonal - Hexagonal Scalenohedral

Crystal Habit:

Pseudocubic rhombohedral {1012} crystals, to 6 mm, may be tabular {0001}, with curved and striated faces. 

Twinning:

None

Physical Properties

Cleavage:

Excellent on {0001} 

Fracture:

Conchoidal

Tenacity:

Brittle

Moh's Hardness:

4.50

Density:

3.01 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Other:

Soluble in acids only after driving off the water in a closed tube.

Optical Properties

Color:

Colorless, white, pink, flesh-pink, pale orange

Transparency:

Translucent to transparent

Luster:

Vitreous, pearly on {0001}

Refractive Index:

1.636 - 1.647  Uniaxial ( + ); May exhibit anomalous biaxial sectors. Basal sections of larger crystals exhibit six radial biaxial sectors. May exhibit zonal banding.

Birefringence:

0.011

Dispersion:

n/a

Pleochroism:

None

Occurances

Geological Setting:

In quartz veins in an Andalusite deposit (Champion mine, California, USA); a product of sulphatic argillic wall-rock alteration in hydrothermal vein and disseminated ore deposits, replacing Apatite (Summitville, Colorado, USA); rarely a cave deposit, formed from guano.

Common Associations:

Topaz, Augelite, Lazulite, Pyrophyllite (Champion mine, California, USA)

Common Impurities:

n/a

Type Locality:

Champion Mine (White Mountain Mine; Jeffrey Mine; Diaspore; Vulcanus; Black Eagle; Champion Sillimanite Mine; Champion Andalusite Mine; Vulcanite Mine; Vulcanite & Vulcanus No. 156; Black Eagle & Vulcanus Nos. 8 and 9 No. 157), White Mountain Peak, White Mts, Mono County, California, USA

Year Discovered:

1937

View mineral photos:

Woodhouseite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Woodhouseite is named after Professor Charles Douglas Woodhouse (1888-1975), American Mineralogist and mineral collector, University of California, Santa Barbara, California, USA. It is a secondary mineral found where sulphatic wall rock alteration occurred in usually low temperature hydrothermal and disseminated ore deposits; also rarely in cave deposits. Woodhouseite is a difficult mineral to classify in that it has both a phosphate anion group and a sulfate anion group. An Anion is an ion with more electrons than protons, giving it a net negative charge. Both of Woodhouseite's anion groups are intricate and essential in its structure but Woodhouseite is generally considered to be in the Phosphate Class due to other classification schemes.

Woodhouseite is mostly found at a single location; the Champion Andalusite Mine on the western slopes of the White Mountain Peak in Mono County, California.Other locations are fairly minor. Woodhouseite typically forms as colorless to flesh-colored pseudocubic rhombohedrons. The crystals may look nearly cubic, but the angles between the faces are not exactly 90 degrees as is required for a true cube. Crystal faces tend to be curved and striated. It forms in Quartz veins with Topaz, Tourmaline, Andalusite and Svanbergite.

Distribution: large crystals from the Champion mine, White Mountains, Mono County, California; in the Summitville district, Rio Grande County, Colorado, USA. From Brumado, Bahia, Brazil. At La Escondida, about 150 km south-southeast of Antofagasta, Chile. From Hökensås, Västergötland, Sweden. In the Ødegården apatite mines, Bamble, Norway. At the Iron Monarch quarry, Iron Knob, South Australia. In the Jade Lotus Cave, Yangshuo, Jiangxi Province, China.
 

  
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