The cushion-shaped brilliants now called old mine cuts developed over centuries. Their facet arrangements reflect the tools and rough available to each cutter.
From early brilliant to old mine
By the eighteenth century, cutters were arranging crown and pavilion facets to draw brightness and fire from cushion-shaped rough. Many stones followed the octahedral crystal, producing a squarish outline with rounded corners, a high crown, small table, deep pavilion and visible culet.
“Old mine” later became a trade term. Today it generally describes the cushion-shaped early brilliant style.
Why the stones vary
Hand tools, weight retention and the original crystal shaped every result. The culet may sit slightly off-centre, the girdle may change thickness and the corners may vary in shape. Record those features individually.
Technology changed the standard
Mechanical bruting, angle gauges and diamond sawing gave cutters more control over round outlines and repeatable proportions in the late nineteenth and early twentieth centuries. The trade moved toward circular brilliants and, later, the modern round brilliant.
Read the individual diamond
Start with measurements, outline, crown, table, depth, culet and condition. Then watch the stone move. Broad flashes, shifting contrast and the relationship between centre and perimeter say more than the label alone.
For technical history, see GIA's research on the development of diamond cut quality grading. Continue with our old mine versus old European cut guide.