Those of you with the fantastic Atlas of Micrometeorites may recognize NMM 976. This bewitching green sherule is an average sized barred olivine (BO-type) micrometeorite with a large metal bead in the front, which is in the middle of this photo by Jan Kihle and me.
Its most unique feature is the large green glassy area. What happened here? A mix between a glass (V-type) and a BO-type micrometeorite? Without any cryptocrystalline (CC-type) middle stage?
I think what may happened here is that the glass is a rest which for some odd reason, did not have time to crystallize before solidification during atmospheric deceleration and cooling. In most cases the combination of entry angle, speed, and mass results in the known micrometeorite textures. But apparently, there are exceptions. I have seen other micrometeorites with a partial glassy rim but not quite like this.
If you have comments or questions, please drop me a line on Facebook, Instagram, or Twitter and I’ll get back to you asap. Meanwhile, enjoy!
Yours truly,
Jon Larsen