Why are pink granite surface plates far less common than black & grey?

[TGTool]

<snip> I have a small 2-ledge 18 x 24 Starrett Pink Granite surface plate here. Darn thing is almost 6" thick!

I understand that the pink granite is more wear resistant but not as stiff as the black so the thickness there may be compensating for that. Nothing they can do the other way to make black any harder.

 

[matthewlee]

There is a batch of pink granite here in Missouri.
Also, if anyone is ever around or passing through, check out elephant rocks park

Elephant Rocks State Park | Missouri State Parks

The elephant-shaped boulders at Elephant Rocks State Park may not be the stars of a circus, but these giant granite boulders are the stars of this unusual park in southeast Missouri. The elephant rocks, which were formed from 1.5-billion-year-old granite, are giant boulders that stand end-to-end...

mostateparks.com