Greetings,

I have observed a shape/form in a piece of cut granite that is a rectangle with parallel sides ( that appear to be centimeters off in measurement). This shape does not seem to be something that is formed in nature. Is there data that supports linear shapes found in nature?

Emitemc2

Very common. For example, Yosemite is full of different kinds of granites with big rectangular pieces like you describe. Would have to look up what minerals they are made of. Definitely formed in nature.

I think they are impure crystals that formed more rapidly--and so got bigger-- than the other crystals in the granite. Not sure. I'm not a geologist.

Granites chosen for counter tops etc, are the opposite--very smooth grained by comparison to what you can find in nature.

Without seeing the piece or knowing the color I can't be certain but it's probably either a hornblende or a feldspar crystal.
Ber