Spurrite
Current inventory:  0 gems
 

  
Spurrite was named by Fred Eugene Wright in 1908 after Josiah Edward Spurr (October 1, 1870 - January 12, 1950), American economic geologist, exoplorer and author. Mount Spurr in southwestern Alaska and Spurr Crater on the moon are also named for him.

Discovered in 1908;   IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

Ca₅(SiO₄)₂(CO₃)

Calcium Silicate Carbonate

Molecular Weight:

444.57 gm

Composition:

Calcium

45.08 %

Ca

63.07 %

CaO

Silicon

12.64 %

Si

27.03 %

SiO₂

Carbon

2.70 %

C

9.90 %

CO₂

Oxygen

39.59 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Silicates

Strunz 8th Ed. ID:

8/B.22-50

Nickel-Strunz 10th Ed. ID:

9.AH.15

9 : SILICATES (Germanates)
A : Nesosilicates
H : Nesosilicates with CO₃, SO₄, PO₄, etc.

Related to:

Dimorpous with Paraspurrite

Members of Group:

n/a

Varieties:

Paraspurrite

Synonyms:

None

Crystal Data

Crystallography:

Monoclinic - Prismatic

Crystal Habit:

Anhedral crystalline, granular or massive.

Twinning:

Polysynthetic twins on {001} and {101}, composition planes {001} or {205}

Physical Properties

Cleavage:

Perfect on {001}, poor on {100}, (001) ^ (100) = 79°

Fracture:

Uneven to Splintery

Tenacity:

Brittle

Moh's Hardness:

5.0

Density:

3.02 (g/cm³)

Luminescence:

Green under SW UV; green cathodoluminescence

Radioactivity:

Not Radioactive

Optical Properties

Color:

White to gray or lavender-gray, violet or purple; colorless in thin section

Transparency:

Transparent to Translucent

Luster:

Vitreous to Resinous

Refractive Index:

1.640 - 1.681  Biaxial ( - )

Birefringence:

0.039 - 0.040

Dispersion:

Relatively weak, crossed, distinct; r > v

Pleochroism:

n/a

Anisotrophism:

n/a

Occurances

Geological Setting:

A product of high-temperature thermal metamorphism along the contact between carbonate rock and mafic magma.

Common Associations:

Gehlenite, Merwinite, Tilleyite, Hillebrandite, Scawtite, Kilchoanite, Rankinite, Larnite, Foshagite, Wollastonite

Common Impurities:

Ti, Al, Fe, Mn, Mg, Na, K

Type Locality:

Terneras Mine, Velardeña, Velardeña District, Mun. de Cuencamé, Durango, Mexico

Year Discovered:

1908

View mineral photos:

Spurrite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Spurrite was first described in 1908 from an occurrence in the Terneras Mine, Velardeña District, Durango, Mexico. It was named by Fred Eugene Wright in 1908 after Josiah Edward Spurr (October 1, 1870 - January 12, 1950), American economic geologist, exoplorer and author. Mount Spurr in southwestern Alaska and Spurr Crater on the moon are also named for him. J. E. Spurr led two expeditions of historic importance in Alaska for the United States Geological Survey. In 1896 he led the first expedition to map and chart the interior of Alaska and in 1898 he went down the length of the Kuskokwim River. After leading these two expeditions Spurr became the world’s leading geological consultant. He published well over a hundred articles in scientific journals, books and monographs. His books were seen as the definitive work on Alaskan minerals during the Alaska Gold Rush.

Spurrite is a calcium silicate carbonte that is typically white to gray in color but may also be found in other colors such as lilac at the Negra Mine, Maconi, Mun. de Cadereyta, Querataro, Mexico; unusually bright violet-purple at the Fuka Mine, Takahashi City, Okayama Prefecture, Japan; bluish-gray at the Crestmore Quarries, Crestmore, Riverside County, California, USA; and lavender-gray from South Sisters Peak, Tres Hermanas District, Luna County, New Mexico, USA. Spurrite gives off a green cathodoluminescence when exposed to shortwave UV light. A unique characteristic of Spurrite is that it abides by two twin laws. Polysynthetic twinning can occur along its (001) axis and another type of twinning can occur parallel to its optical axes.

Spurrite is also found at Seekante, Mayener Feld, Southern lava flow, Bellerberg volcano, Ettringen, Mayen, Eifel, Rhineland-Palatinate, Germany; Velardeña District, Mun. de Cuencamé, Durango, Mexico; Carneal, Glenoe, Co. Antrim, Northern Ireland, UK; and Christmas Mountains, Brewster County, Texas, USA.
 

  
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