TY - JOUR
T1 - A high-pressure, clinopyroxene-structured polymorph of albite in highly shocked terrestrial and meteoritic rocks
AU - Ma, Chi
AU - Tschauner, Oliver
AU - Kong, Mihye
AU - Beckett, John R.
AU - Greenberg, Eran
AU - Prakapenka, Vitali B.
AU - Lee, Yongjae
N1 - Publisher Copyright:
© 2022 Mineralogical Society of America.
PY - 2022/4/1
Y1 - 2022/4/1
N2 - Abstraact: Clinopyroxenes with excess Si have been described in run products from high-pressure experiments and inferred to have existed in nature from retrograde transformation phases. Here, we present the discovery of albitic jadeite, (Na,Ca,□1/4)(Al,Si)Si2O6 - the first natural, sodic clinopyroxene with excess Si occupying the octahedral cation site, M1, and a corresponding ¼ vacancy on the M2-site in the Ries impact structure and in a suite of L6 ordinary chondrites, EET 13014, EET 13052, NWA 1662, and TIL 08001. Garnet compositions in these samples indicate shock pressures of 18-22 GPa. Based on our survey, albitic jadeite is likely to be rather common in terrestrial and meteoritic shock-metamorphic environments. Shock-generated jadeite should be reexamined with respect to excess Si.
AB - Abstraact: Clinopyroxenes with excess Si have been described in run products from high-pressure experiments and inferred to have existed in nature from retrograde transformation phases. Here, we present the discovery of albitic jadeite, (Na,Ca,□1/4)(Al,Si)Si2O6 - the first natural, sodic clinopyroxene with excess Si occupying the octahedral cation site, M1, and a corresponding ¼ vacancy on the M2-site in the Ries impact structure and in a suite of L6 ordinary chondrites, EET 13014, EET 13052, NWA 1662, and TIL 08001. Garnet compositions in these samples indicate shock pressures of 18-22 GPa. Based on our survey, albitic jadeite is likely to be rather common in terrestrial and meteoritic shock-metamorphic environments. Shock-generated jadeite should be reexamined with respect to excess Si.
KW - (Na,Ca,□)(Al,Si)SiO
KW - Albitic jadeite
KW - L6 ordinary chondrites
KW - Ries impact structure
KW - high-pressure clinopyroxene
KW - shock-induced phase
UR - http://www.scopus.com/inward/record.url?scp=85111606958&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85111606958&partnerID=8YFLogxK
U2 - 10.2138/am-2021-7925
DO - 10.2138/am-2021-7925
M3 - Article
AN - SCOPUS:85111606958
SN - 0003-004X
VL - 107
SP - 625
EP - 630
JO - American Mineralogist
JF - American Mineralogist
IS - 4
ER -