The stones did pass the test on the presidium This is small.

GOLD PURITY DISCLAIMER

Items made before 1981 go by the purity standards used in the 1906 law. Older items had even looser laws, if any, in place about precious metals content.

Items could technically be marked for purity but range anywhere from .5 - 1.0 kt less than stamped. I’ve found cases where it’s been a little more of a deficit in much older items and/or depending on country of origin and their standards

I don’t own an XRF or xray machine to tell the exact purity of my items. I do test with acid to verify solid gold vs plate, filled, rolled etc.