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Hi Andy.
Hi Simon.
How are you getting on with that moon rock?
OK, well, I'm having problems identifying the olivine
OK - erm - lets take a look at it together. I'll take control...
There are quite a few olivines, they're quite small and they're embedded in the pyroxenes, Andy.
Lets move across to the rotation, in fact even in cross-polarised light you can't see it.
Can you take control and go into that rotation?
Now you can see just there the pyroxene's going into extinction.
So you're saying the yellow crystal's olivine? But how do I know its not a pyroxene?
Its the cleavage; you can see the cleavage in the pyroxene - its got long straight cleavage; the olivine has that rounded shape and no cleavage - you can see cracks just going across it.