Stone in wax casting results

Dear Orchidians,

I just made a few casts with stone in wax. I found that most of the
stones came out with a film of metal on the back, rendering them with
no shine.

I found that taking out that film of metal is very hard. Is there
any way to keep that from happening? I have seen castings of stone in
wax that are flawless.

Thank you for your help.

Best regards,
Juan Pablo Martenez Mansilla
Guatemala Ciudad, Guatemala, Centroamerica.
Tels.:++(502) 2439 7003 - 2439 7007
Fax.: ++(502) 2439 7005