A weathered sign in the Minnesota River Valley proudly proclaims: “World’s Oldest Rock.” Erected in 1975, it marks a 3.8-billion-year-old gneiss — or so scientists thought. Turns out ...

It is predominately underlain by a bedrock of kyanite-bearing mica schist which is thought to be the primary source of the rutile which is then concentrated and upgraded in the overlying saprolite ...

Manager -Sales and Application at Metamorphic Rock tools Authorized Distributors for Boart Longyear Top hammer tools and Down the hole drilling tools manufacturing ...

Sean: Oh, we're in deep schist.