60625 (7) Impact Melt Breccia
We would like to thank the following for the use of this sample:
60625 is a white rock collected as a rake sample from near the Lunar Module. The composition shows it is plagioclase-rich, but it also has high content of rare earth elements (i.e. it is an unusual breccia or impact melt rock). Texturally it contains irregular oikocrysts (pyroxene) up to 1 mm, enclosing euhedral plagioclase chadocrysts. Some plagioclase is shocked. The mineralogy is 65% plagioclase (An95), 17% olivine (Fo77) and 16% pyroxene (Wo7En75Fs18) with minor ilmenite, armalcolite and a K-rich phase. In reflected light, metallic iron can be seen to forms rounded crystals mantled by troilite.
The sample weighed 117 grams before analysis and has not been dated.
Further details of this and other Apollo samples are here: http://curator.jsc.nasa.gov/lunar/
Our thin section image shows a sequence of numbers (1-3) that have been scribed on the glass behind the three rock fragments. In places the thin section is thick so between crossed polars some plagioclase crystals are yellow instead of shades of grey.
Ma = Millions of years ago
Rock forming mineral:
- metallic iron,