12052 (7) - Pigeonite basalt
 >View Microscope
Fact sheet
Description: 

12052 is composed of euhedral and skeletal phenocrysts of olivine and clinopyroxene (pigeonite cores with augite rims) surrounded by a groundmass including high-iron clinopyroxene, chrome spinel, ilmenite, pyroxferroite and anorthite. Compositionally zoned phenocrysts of pyroxene (3-4 mm) occur in random orientation, together with skeletal or rounded olivine crystals (1 mm) in a finer-grained variolitic groundmass of pyroxene-plagioclase and opaque minerals, chiefly ilmenite, which are parallel to the pyroxene laths. Pigeonite cores have sharp boundaries with augite rims. Ilmenite occurs as lath-shaped crystals up to 400 micron long and 50 micron wide.

The sample weighed 1866 grams before analysis and is 3.28±0.19 billion years old (Rb/Sr).

Further details of this and other Apollo samples are here: http://curator.jsc.nasa.gov/lunar/

In Place
In Time
Accuracy:
Timescale:
Not known
Ma = Millions of years ago
In Focus
Collection:
What\
Type:
Type: 
igneous
What\
Rock-forming minerals:

Rock forming mineral:

What\
Accessory minerals:

Accessory minerals:

What\