- journal_title：European Journal of Mineralogy
- Contributor：Xia Wang ; Guang Hai Shi ; Deng Feng Qiu ; Jing Wang ; Wen Yuan Cui
- Publisher：E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers
- Date：2012-
- Format：text/html
- Language：en
- Identifier：10.1127/0935-1221/2011/0023-2157
- journal_abbrev：Eur J Mineral
- issn：0935-1221
- volume：24
- issue：2
- firstpage：237
- section：Articles
A new rock type in the Hpakant jadeitite area, Myanmar is identified as jadeitized rodingite. The rock consists of omphacite, garnet and jadeite, with minor allanite-(La), phlogopite, zeolite, chlorite, and a barian mineral. The garnet contains more than 80 mol% of the grossular end-member. Omphacite has variable composition and is Mg-rich (XMg-aver = 90), while jadeite contains 82–92 mol% of jadeite end-member. Petrography shows that the garnet formed before omphacite, and many omphacite grains have jadeite rims or occur as island surrounded by replacement jadeite, indicating that a jadeitization event occurred subsequent to grossular and omphacite formation. Considering the geochemical interpretation that the protolith of rodingite (gabbro, plagiogranite or pyroxenite) has considerable Na2O (mostly >2.0 wt% bulk), whereas rodingite has low Na2O (mostly <1.0 wt% bulk), serpentinization-related rodingitization could locally yield Na-rich fluids, which could be an additional source for the fluids for jadeitite formation, and may play an important role in fluid-rock interactions in subduction zones.