Californite (a variety of Vesuvianite)
Current inventory:  1 gem
 

  
Californite is named after its occurance in California, USA. Vesuvianite is named after its locality of discovery on Mt. Vesuvius, Campania, Italy.

Discovered in 1795;   IMA status:  Not Valid (a variety of Vesuvianite)

Chemistry

Chemical Formula:

Ca₁₉Al₄Fe(Al,Mg,Fe)₈Si₁₈O₇

Calcium Aluminum Iron Silicate

Molecular Weight:

1,422.09 gm

Composition:

Calcium

28.18 %

Ca

39.43 %

CaO

Magnesium

3.42 %

Mg

5.67 %

MgO

Aluminum

7.59 %

Al

14.34 %

Al₂O₃

Silicon

17.77 %

Si

38.03 %

SiO₂

Hydrogen

0.28 %

H

2.53 %

H₂O

Oxygen

42.75 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Silicates (Germanates)

Strunz 8th Ed. ID:

8/C.26-10

Nickel-Strunz 10th Ed. ID:

9.BG.35

9 : SILICATES (Germanates)
B : Sorosilicates
G : Sorosilicates with mixed SiO₄ and Si₂O₇ groups; cations in octahedral [6] and greater coordination

Related to:

Vesuvianite Group. Hydroxyl analogue of Fluorvesuvianite.

Members of Group:

Vesuvianite Group: Fluorvesuvianite, Manganvesuvianite, Vesuvianite, Wiluite

Varieties:

None

Synonyms:

American Jade, California Jade, Vesuvianite Jade

Crystal Data

Crystallography:

Tetragonal - Dipyramidal

Crystal Habit:

Vesuvianite: Crystals commonly as short pyramidal to long prismatic crystals, to 15 cm, morphologically complex, with up to 30 forms reported on one crystal; columnar, granular, massive. Californite is found in massive form, not as crystals.

Twinning:

Vesuvianite: Twinned domains observed at a very fine scale.

Physical Properties

Cleavage:

Indistinct on {110}, {100} and {001]

Fracture:

Irregular/Uneven, Sub-conchoidal

Tenacity:

Brittle

Moh's Hardness:

6.0 - 7.0

Density:

3.32 - 3.47 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Optical Properties

Color:

Green, Yellowish Green

Transparency:

Transparent, Translucent, Opaque

Luster:

Vitreous, Resinous

Refractive Index:

1.698 - 1.742  Uniaxial ( -/+ ) and Biaxial

Birefringence:

0.0040 - 0.0060

Dispersion:

Strong; 0.019 - 0.025

Pleochroism:

Weak; O = colorless to yellowish, E = yellowish, greenish, brownish

Occurances

Geological Setting:

Vesuvianite: In skarns formed during contact or regional metamorphism of limestones; in garnetized gabbros, mafic and ultramafic rocks, and serpentinites; uncommon in alkalic igneous rocks.

Common Associations:

Grossular, Diopside, Wollastonite, Epidote, Scapolite, Spinel, Calcite

Common Impurities:

Fe, Be, B, F, Cu, Li, Na, K, Mn, Ti, Cr, Zn, H₂O

Type Locality:

Californite: Happy Camp, Siskiyou County, California, USA
Vesuvianite: Monte Somma, Somma-Vesuvius Complex, Naples Province, Campania, Italy

Year Discovered:

Californite: Unknown
Vesuvianite: 1795

View mineral photos:

Californite Mineral Photos and Locations
Vesuvianite Mineral Photos and Locations

More Information

Mindat.org (Californite)
Mindat.org (Vesuvianite)
Webmineral.com (Vesuvianite)

Californite, also known as California Jade, American Jade or Vesuvianite Jade, is a rare variety of Vesuvianite that is only found in California. This bright green translucent to opaque material comes from several locations in and around Happy Camp, Siskiyou County; at the Pulga deposit, Butte County; and at Sky Blue Hill, Crestmore, Riverside County, California, USA. It is usually found as opaque, massive material suitable for cabochons, rarely as facet grade crystals. The cabochons are very attractive and look very similar to Jade. Faceted gems are usually translucent and silky and may resemble green Prehnite. Vesuvianite (also known as Idocrase) is found in colors ranging from green to brown and rarely blue (Cyprine).
 

  
Californite gems for sale: