15610 (6) Coarse Olivine Basalt
We would like to thank the following for the use of this sample:
15610 is a walnut-sized sample (>1 cm) extracted from the large 15600 soil sample. It was collected together with other fragments taken as rake samples from an adjacent area (15633, 15641, 15643 and 15663). They are grouped together because they are relatively coarse-grained samples of the abundant olivine normative Apollo 15 basalt clan. Most olivine grains are less than 1mm in length; the larger ones contain silicate melt inclusions. Pyroxene grains are up to 2mm in length and somewhat elongate. They are chemically zoned from pigeonite to Fe-rich augite (see rotation 1). Plagioclase grains up to 3mm, poikilitically enclose small pyroxene, otherwise intergrown with pyroxene. Chromite is found in pyroxene and is overgrown with ulvospinel when it is interstitial. Minor phases include cristobalite, fayalite, ilmenite, troilite, metallic iron and Fe-rich glass.
The sample weighed 1.5 grams before analysis and has not been dated.
Further details of this and other Apollo samples are here: http://curator.jsc.nasa.gov/lunar/
Ma = Millions of years ago
Rock forming mineral:
- metallic iron