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Jadeite deposits of the clear creek area, New Idria district, San Benito county, California

June 1, 1961

Tectonic inclusions within the New Idria serpentine body contain jadeite in two distinct assemblages: (1) Lenslike inclusions containing a monomineralic green jadeite core surrounded by a calc-silicate rim. (2) Jadeite veins cross-cutting albite-crossite schist inclusions. In these veins jadeite coexists with low albite; green jadeite (Jd 75 Ac+Di+He 25) coexists with low albite within the host schist.

Albite schists are related to the pre-metamorphic keratophyres and it can be shown that desilication of such rocks produces a bulk composition similar to that of jadeite. Metamor-phism of keratophyric tectonic inclusions within serpentine produced jadeite-albite schists along margins of the inclusions. Jadeite-albite veins formed from mobilized liquids rich in the jadeite molecule and deficient in water. Geological evidence such as would indicate extreme pressures or temperatures during jadeite formation is lacking; rather, a low silica and dry system allowed its formation at reduced temperatures and pressures.

Publication Year 1961
Title Jadeite deposits of the clear creek area, New Idria district, San Benito county, California
DOI 10.1093/petrology/2.2.209
Authors R. G. Coleman
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Petrology
Index ID 70220599
Record Source USGS Publications Warehouse
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