Diopside

Source: Wikipedia, the free encyclopedia.
Diopside
2V angle
Measured: 58° to 63°
DispersionWeak to distinct, r>v
Melting point1391 °C
References[2][3][4]

Diopside is a monoclinic pyroxene

specific gravity of 3.25 to 3.55. It is transparent to translucent with indices of refraction
of nα=1.663–1.699, nβ=1.671–1.705, and nγ=1.693–1.728. The optic angle is 58° to 63°.

Formation

Diopside crystal from De Kalb, New York (size: 4.3 x 3.3 x 1.9 cm)

Diopside is found in

igneous rocks, and diopside-rich augite is common in mafic rocks, such as olivine basalt and andesite. Diopside is also found in a variety of metamorphic rocks, such as in contact metamorphosed skarns developed from high silica dolomites. It is an important mineral in the Earth's mantle and is common in peridotite xenoliths
erupted in kimberlite and alkali basalt.

Mineralogy and occurrence

A green diopside found in Outokumpu, Finland

Diopside is a precursor of

magmatic differentiation;[6] it can react with hydrous solutions of magnesium and chlorine to yield chrysotile by heating at 600 °C for three days.[7] Some vermiculite deposits, most notably those in Libby, Montana, are contaminated with chrysotile (as well as other forms of asbestos) that formed from diopside.[8]

At relatively high temperatures, there is a

orthopyroxene. The calcium/(calcium+magnesium+iron) ratio in diopside that formed with one of these other two pyroxenes is particularly sensitive to temperature above 900 °C, and compositions of diopside in peridotite xenoliths have been important in reconstructions of temperatures in the Earth's mantle
.

Chrome diopside ((Ca,Na,Mg,Fe,Cr)
2(Si,Al)
2O
6) is a common constituent of

Green River Basin of Wyoming. Much chromian diopside from the Green River Basin localities and several of the State Line Kimberlites have been gem in character.[9][citation needed
]

As a gem

semi-precious stone.[10]

Violane is a manganese-rich variety of diopside, violet to light blue in color.[11]

Etymology and history

Diopside derives its name from the Greek dis, "twice", and òpsè, "face" in reference to the two ways of orienting the vertical prism.

Diopside was discovered and first described about 1800, by Brazilian naturalist

Jose Bonifacio de Andrada e Silva
.

Potential uses

Wikimedia Commons has media related to Diopside.

Diopside based ceramics and glass-ceramics have potential applications in various technological areas. A diopside based glass-ceramic named 'silceram' was produced by scientists from Imperial College, UK during the 1980s from blast furnace slag and other waste products. They also produced glass-ceramic is a potential structural material. Similarly, diopside based ceramics and glass-ceramics have potential applications in the field of biomaterials, nuclear waste immobilization and sealing materials in solid oxide fuel cells.

References

  1. S2CID 235729616
    .
  2. ISBN 0-04-549011-2
    .
  3. ^ Mindat page for Diopside
  4. ^ Handbook of Mineralogy
  5. doi:10.1111/j.1551-2916.2007.02166.x
    .
  6. S2CID 128604912
    .
  7. doi:10.1127/ejm/9/1/0083
    .
  8. ^ "Asbestos in Your Home". United States Environmental Protection Agency. 2003. Archived from the original on October 8, 2006. Retrieved 2007-11-20.
  9. ^ Hausel, W. Dan (2006). Geology and Geochemistry of the Leucite Hills Lamproitic field, Rocks Springs Uplift, Wyoming. laramie, Wyoming: Wyoming geological survey.
  10. ISBN 978-0-06-196216-5
    .
  11. ^ Mindat page for Violane
  • S. Carter, C.B. Ponton, R.D. Rawlings, P.S. Rogers, Microstructure, chemistry, elastic properties and internal-friction of silceram glass-ceramics, Journal of Materials Science 23 (1988) 2622–2630.
  • T. Nonami, S. Tsutsumi, Study of diopside ceramics for biomaterials, Journal of Materials Science: Materials in Medicine 10 (1999) 475–479.
  • A. Goel, D.U. Tulyaganov, V.V. Kharton, A.A. Yaremchenko, J.M.F. Ferreira, Electrical behaviour of aluminosilicate glass-ceramic sealants and their interaction with metallic SOFC interconnects, Journal of Power Sources 195 (2010) 522–526.
  • Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., Wiley, pp 403–404,
    ISBN 0-471-80580-7
  • Mindat: Chromian diopside, with locales
  • Webmineral
  • Chrome Diopside on gemstone.org
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