15555 (256) Olivine Basalt
 >View Microscope
Fact sheet
Description: 

15555 (called “Great Scott”, after the collector Dave Scott) is one of the largest samples returned from the moon and is representative of the basaltic samples found on the mare surface at Apollo 15. The bulk composition of 15555 is thought to represent that of a primitive volcanic liquid. It contains olivine and pyroxene phenocrysts and has a sub-ophitic, basaltic texture. Two generations of olivine are present. Both olivine and pyroxene crystals are chemically zoned. There is little evidence for shock in the minerals. Accessory minerals include cristobalite, ilmenite, ulvospinel, chromite, troilite and metallic iron. An unidentified Zr-Ti-Fe mineral (“phase Y”) has also been reported.

The sample weighed 9614 grams before analysis. It has been dated at 3.33±0.05 billion years (Ar/Ar).

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\