|
As the photo at right illustrates,
this fossilized horn coral can cut into gorgeous cabochons. This is very difficult
material to find, because the mine where it comes from was closed due to being
included into a National Monument. We were fortunate to obtain this rough from
old collections.
This fossil coral comes from the Silurian
Age which dates to 390 million years old and falls within the Paleozoic Era.
Fossil Horn Coral is agatized. So, it cuts like agate and takes
a fine polish with tin or cerium oxide and diamond. Mohs hardness 6.5 to 7.
|