Perhaps He can tell us
If it is the only one rock ,He send for assay it.
But when I exploring a mine or a land
if i notice something interesting
For me only (Gold , silver and Gemstone)
I bring with me lot of Ziploc bags
and i collecting many examples
from different parts of that mine or land
Outside and inside the
mine ,if it is any.
then send it to a lab for testing
that the only way to be sure
if it is worthy to work on there
A good advice to Him
collecting as many examples You want
send it the lab
after You can make a choice
I know everything cost money
but i preferred to sure
than sorry.