An old mine diamond cut is one in which the diamond is fashioned into a square type girdle with slightly rounded corners. They have a high crown, large and flat cutlet and a small table. This type of diamond cut was first made during the 1700s.
An old mine diamond cut is close in appearance to the more modern cushion cut and was common during Victorian and Georgian eras. The old mine cut is considered an antique diamond cut, as are the rose, single and old European cuts, in addition to the modern round brilliant cut, which began in the early 1900s.