[meteorite-list] Size of diamonds in ureilites

[bernd.pauli at paulinet.de]

Hello Mark and List,

GOODRICH C.A. (1992) Ureilites: A critical review (Meteoritics 27-4, 1992, 327-352):

"Graphite is the most common polymorph  of carbon in ureilites. Vdovykin (1970) found traces
of chaoite and organic carbon compounds in Haverö, Novo Urei, Dyalpur and Goalpara. Diamond
and lonsdaleite have been identified in Kenna (Gibson, 1976; Berkley et al., 1976), Haverö (Marvin
and Wood, 1972) and Goalpara (Marvin and Wood, 1972) by X-ray diffraction and electron microprobe
techniques. Diamond and lonsdaleite occur as small (< 1-3 µm) anhedral  to subhedral grains within
a fine-grained matrix of graphite and lesser silicate (Marvin and Wood, 1972; Berkley et al., 1976)".


Best wishes,

Bernd