TY - JOUR
T1 - A monoclinic pst-stishovite polymorph of silica in the Shergotty meteorite
AU - El Goresy, Ahmed
AU - Dubrovinsky, Leonid
AU - Sharp, Thomas
AU - Saxena, Surendra K.
AU - Chen, Ming
PY - 2000/6/2
Y1 - 2000/6/2
N2 - A post-stishovite phase of silica was identified in the Shergotty meteorite by x-ray diffraction and field emission scanning electron microscopy. The diffraction pattern revealed a monoclinic lattice, similar to the baddeleyite-structured polymorph with the cell parameters a = 4.375(1) angstroms, b = 4.584(1) angstroms, c = 4.708(1) angstroms, β= 99.97(3), π = 4.30(2) grams per cubic centimeter, where the numbers in parentheses are the maximum deviations. Transmission electron microscopy investigations indicate the presence of the α-lead dioxide-like polymorph, stishovite, and secondary cristobalite in the same silica grain. The mixture of high-density polymorphs suggests that several post-stishovite phases were formed during the shock event on the Shergotty parent body.
AB - A post-stishovite phase of silica was identified in the Shergotty meteorite by x-ray diffraction and field emission scanning electron microscopy. The diffraction pattern revealed a monoclinic lattice, similar to the baddeleyite-structured polymorph with the cell parameters a = 4.375(1) angstroms, b = 4.584(1) angstroms, c = 4.708(1) angstroms, β= 99.97(3), π = 4.30(2) grams per cubic centimeter, where the numbers in parentheses are the maximum deviations. Transmission electron microscopy investigations indicate the presence of the α-lead dioxide-like polymorph, stishovite, and secondary cristobalite in the same silica grain. The mixture of high-density polymorphs suggests that several post-stishovite phases were formed during the shock event on the Shergotty parent body.
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U2 - 10.1126/science.288.5471.1632
DO - 10.1126/science.288.5471.1632
M3 - Article
AN - SCOPUS:0034595876
VL - 288
SP - 1632
EP - 1634
JO - Science
JF - Science
SN - 0036-8075
IS - 5471
ER -