Hello I am cutting Labradorithe. My rough is not very good quality
from Madagascar. After I cut a stone I solve the dopping wax with
Methylated spirit. now after about a month the first stone I cut shows
a black line. There was a fine crack before but it seems that after
some time the crack turns black. Am I just mad and did not see the
line earlier or is there some kind of oxidation going on?
What can I do to prevent other stones from the same fate?
Wax? Glue? what does a professional lapidary do? Can I clean the crack
that is black already?
I am grateful for any help!