Clinohumite is an uncommon member of the humite group, a magnesium silicate according to the chemical formula (Mg, Fe)9(SiO4)4(F,OH)2. The formula can be thought of as four olivine (Mg2SiO4), plus one brucite (Mg(OH)2). Indeed, the mineral is essentially a hydrated olivine and occurs in altered ultramafic rocks and carbonatites. Most commonly found as tiny indistinct grains, large euhedral clinohumite crystals are sought by collectors and occasionally fashioned into bright, yellow-orange gemstones. Only two sources of gem-quality material are known: the Pamir Mountains of Tajikistan, and the Taymyr region of northern Siberia. It is one of two humite group minerals that have been cut into gems, the other being the much more common chondrodite.
Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
Mineralienatlas
Handbook of Mineralogy
Clinohumite on Mindat.org
Clinohumite on Webmineral
Deer, W.A., R.A. Howie, and J. Zussman (1966). An Introduction to the Rock Forming Minerals. London: Longsman, Green and Co., Ltd.
Roberts, W.L., G.R. Rapps, Jr., and J. Weber (1975). Encyclopedia of Minerals. New York: Van Nostrand Reinhyold Company.
Arem, Joel E. (1977). Color Encyclopedia of Gemstones. Van Nostrand Reinhold Company, New York, 149 pages.
Henn, U., Hyršl, J., and Milisenda, C. (2000). "Gem-quality clinohumite from Tajikistan and the Taymyr region, Northern Siberia." Journal of Gemmology, Vol. 27, No. 6, pp. 335–340.
Webster, R., Read, P. G. (Ed.) (2000). Gems: Their Sources, Descriptions and Identification (5th ed.), p. 327. Butterworth-Heinemann, Great Britain. ISBN 0-7506-1674-1.
Luth, R. W. (2003) Mantle Volatiles – Distribution and Consequences. In The Mantle and Core (ed. R. W. Carlson) Vol. 2 Treatise on Geochemistry (eds. H. D. Holland and K. K. Turekian), Elsevier-Pergamon, Oxford.ISBN 0-08-043751-6
J.R. Smyth, D.J. Frost, F. Nestola, C.M. Holl and G. Bromiley (2006), "Olivine hydration in the deep upper mantle: Effects of temperature and silica activity." Geophysical Research Letters 33, L15301.
Pradeepkumar, A P., Krishnanath, R. (2000). "A Pan-African 'Humite Epoch' in East Gondwana: implications for Neoproterozoic Gondwana geometry." Journal of Geodynamics, Vol. 29, No. 1-2, pp. 43–62 [1].
Berry, A.J. and James, M. (2001) "Refinement of hydrogen positions in synthetic hydroxyl-clinohumite by powder neutron diffraction." American Mineralogist, 86, pp. 181–184.
Friedrich, A., Lager, G.A., Kunz, M., Chakoumakos, B.C., Smyth, J.R., and Schultz, A.J. (2001) "Temperature-dependent single-crystal neutron diffraction study of natural chondrodite and clinohumites." American Mineralogist, 86, pp. 981–989.