Testing for Black Diamonds

good day sir,please gave me a clarification regarding the black diamond?if this carbonado is significantly alone to the rock or there are some other color gem are present toghether in the rock were black diamonds are found?because my neighbor mountain were found in the rock surface a gem which been test to private agent and are found to be carbonado.And there are some color gem is found,brown color and colorless gem invaded in a hard rock.my Question are: is it our mountain may possible also to diamond because in 1995 my cousin was curious to the rock found in our mountain which he seem to suspect thesame coal they transport from country to country.And when he bring the rock to beauru of mines and minerals for testing.It was positive to be coal mine.our land mountain are about 10 hectares or more.Is it also possible to diamond same what they found in our neighbor mountain?