NWA 16100 was 1,922 grams, in three pieces, of olivine bearing diogenite-melt rock. It contains vesicles which are apparent in this cut fragment and whiskers that are easily seen in thin section under magnification.
This cut fragment was sourced from Jason Whitcomb of https://www.handfulofspace.com/
Our excellent thin section was made by Erik Karadeema https://high-mesa-petrographics.square.site/ It is a standard 27 x 46 mm size, “double polished” and not covered.
The melt rock is fine grained.
Top right corner in cross-polarized light (XPL). Field of view (FOV) is 3.1 mm wide.
This is the bright yellow grain above. Note the whiskers on the dark inclusions. FOV = 0.3mm. XPL
The whiskers are not of uniform width along their length. FOV=0.1mm. XPL
FOV=0.05mm. Plane polarized light (PPL)
We will look closer at the green elongated grain in the center. FOV=3.1mm. XPL
FOV=0.5mm. XPL
Whiskers are seen on the inclusions at lower left. One expert I asked about these hadn’t seen them before and, predictably, asked if they’d been microprobed. Not that I know of. Maybe someone should do a paper on them. FOV=0.4mm. PPL
Whiskers possibly align with the mineral grain’s crystal structure. FOV=0.2mm. PPL
Note the center grain with three dark inclusions. FOV=3.1mm. PPL
Whiskers often appear more robust in one direction than in the other. FOV=0.3mm. PPL
Whiskers do not all lie in the plane of the section surface. These start from the body of the inclusion near the top surface of the sample and extend downwardly at roughly 45 degrees. FOV=0.15mm. PPL
FOV=0.3mm. PPL
Robust whiskers aligned NW-SE. FOV=0.15mm. PPL.
FOV=0.3mm. PPL
FOV=0.3mm. PPL
FOV=0.3mm. XPL
FOV=0.075mm. XPL
