Sandra D. Connors (sconners@coldspringusa.com) who has much wisdom in selling stone to sculptors (Jesus Morales, Candyce Garrett, Jason Quigno, Tom Small, Sue Taves, Carl Nelson, etc..) and is the holder of the keys to the Coldspring Granite production boneyard (AKA candy store) in Marble Falls Texas.
https://www.coldspringusa.com/quarry-materials/block-sales/
They have quarries and offices in North America and ship stone from all over the world.
Corporate Headquarters
17482 Granite West Road
Cold Spring, MN 56320
https://www.coldspringusa.com/