Black Marble Liquor Decanters (2)

Looking for information on a decanter set. With stoppers, they measure 10" tall and 3" wide square. Black, opaque marble glass except the underside (clear). They are labeled with a semi-circular metal band around the neck, one rye, one gin. There was at least one other that got broken and discarded. The only markings to be found outside of the patterning, is a 9 or 6 raised numeral on the underside of one piece and the stoppers have raised 2 and 3 respectively. Stoppers are fitted into well aged cork. They were purchased at a garage sale approx 20 yrs ago, no info from previous owners. Any help identifying or a point in the right direction would be much appreciated.