Why this rock is probably not a meteorite:

Like some other rocks depicted here, this rock bears some resemblance to a feldspathic lunar meteorite because most such meteorites are regolith breccias. What distinguishes this rock from a lunar regolith breccia is the shape of the large white grains. Many of them have very geometric shapes: rectangles and parallelograms. That's a sure sign of a crystal that grew in a melt. Regolith breccias consist of pieces of broken rock that get compressed into a solid rock by the heat and pressure of a meteoroid impact. Such a mechanism cannot produce or preserve geometrically shaped clasts.
What is it?

Another porphyritic volcanic rock like nos. 084 and 129.


Prepared by:

Randy L. Korotev

Department of Earth and Planetary Sciences
Washington University in St. Louis

Please don't contact me about the meteorite you think you’ve found until you read this and this.