Tag Archive for 'Ureilite'

Images of graphite, lonsdaleite, and diamond in ureilite meteorites: (A) reflected light image showing folded crystalline graphite, with fold morphology defined by graphite cleavage; different shading in the graphite is produced by axial planar kink bands; (B) reflected light image (stacked foci) showing an example of the inherited fold morphology preserved in lonsdaleite; (C) cathodoluminescence map of the same area as (B) indicating different phases of carbon, where the green regions are lonsdaleite and the red areas on the periphery (including the purple dashed circle) are cubic diamond (blue is the cathodoluminescence response from olivine); (D) scanning TEM image of a region cut out of the area indicated by yellow circle in (C), highlighting dark lonsdaleite crystals. Image credit: Tomkins et al., doi: 10.1073/pnas.2208814119.

Strange Meteoritic Diamonds Came from Mantle of Destroyed Dwarf Planet, Study Says

Sep 13, 2022 by News Staff

Lonsdaleite, a rare hexagonal form of diamond found in ureilite meteorites, formed shortly after an inner solar system dwarf planet collided with a large...

The Almahata Sitta meteorite. Image credit: Peter Jenniskens.

Diamond-Bearing ‘Almahata Sitta’ Meteorites Came from Long-Lost Protoplanet

Apr 19, 2018 by News Staff

The Almahata Sitta meteorites — diamond-bearing space rock fragments that rained down on the Nubian Desert in Sudan in 2008 — are remnants...