Mineralogy and paragenesis of minerals from the marble-hosted ruby deposits of Myanmar

Harlow, Rossman, and Castoro examining gem rough at Namya (Nanyaseik), Myanmar.

Dr. Harlow journeyed to Myanmar (Burma) with research associate George R. Rossman, Cal Tech, and gemologist Loretta Castoro in March 2002 to visit ruby and jade mines. Returned specimens are being studied as part of two research projects: 1) the mineralogy of the ruby deposits of Myanmar with attention to the role of metasomatism by magmatic events and 2) the origin and geochemistry of the jadeitite deposits of Myanmar. A large collection of samples from the Mogok stone tract added to the AMNH mineral collection point overwhelmingly to a metasomatic signature in the origin of ruby, as well as magmatic involvement in the hosting of moonstone, scapolite, blue cancrinite, etc. in marble of the Mogok belt. Painite, a rare gem species (CaZrBAl₉O₁₈) is found with sinhalite, baddeleyite, zirconalite, tourmaline and ruby in a skarn relationship between the Mogok marble and a late (~15 Ma) leucogranite. Comparative studies are being carried out on the corundums, spinels, and other gem gravel concentrates from Sagyin, Mogok, Namya (Nayaseik), Myanmar and Luc Yen, Vietnam.

Abstracts:

Avé Lallemant, H.G., Harlow, G.E., Sorensen, S.S., Sisson, V.B., Kane, R. E., Han Htun, Myint Soe (2000) The Nansibon Jade Mines, Myanmar: Structure and Tectonics. EOS 81, 48, F1108. (PDF)

Harlow, G.E. (2000) The Mogok Stone Tract, Myanmar: Minerals with complex parageneses. Minerals and Museums 4, Dec. 2-7, 2000; Melbourne, NSW, Australia, Program & Abstract Vol., 50.(PDF)

Harlow, G.E., Sahm, E. and Hunt, J. (2005) CL in support of interpreting gem deposits. Goldschmidt 2005, Abstracts, A594. (PDF)

Rossman, G.R., Naung, S., Harlow, G.E. and Hunt, J. (2005) Painite (CaZrBAl₉O₁₈): A second source in Myanmar and Metasomatic Origins. Goldschmidt 2005, Abstracts, A278. (PDF)

Harlow, G.E., Pamukcu, A., Saw Naung, Kyaw Thu (2006) Mineral assemblages and the origin of ruby in the Mogok Stone Tract, Myanmar. GIA Gemological Research Conference, Aug. 26-27, San Diego, CA; Abstract. (PDF)