The phones in Australia are ringing off the hook, police say, after a local jeweler was arrested for allegedly selling clarity-enhanced stones with phony Gemological Institute of America (GIA) certificates.

At least 12 more stones, supplied by the public, are being analyzed.

The certificates were said to emanate from Israeli dealer Moti Weisbrot. GIA has initiated criminal prosecution against Weisbrot in Italy. Todd Douglas Jacobs, a Chicago-area GIA student whose signature was on the reports, has been suspended from the school pending an investigation.

The Australian gem industry has advised consumers to buy only from reputable jewelers and to have any gem they are not sure of appraised by an expert.