Perhaps the most common diamond cut from the early 18th century to the late 19th century, the old mine cut evokes the past, when diamonds were measured by eye and cut by hand. Recognized by their squarish shape, the old mine cut diamond has 58- facets like today’s modern round brilliant cut diamond, but that’s where the similarity ends. In addition to a different shape, an old mine cut has different diamond proportions: it typically has a smaller table, larger culet and higher crown. It also has short lower half facets and a girdle that is very thin in places, and, as a result of these factors, an old mine cut diamond has a very distinctive look. Due to the shape of the rough and because the diamonds were handcrafted, the dimensions vary from stone to stone. This makes every old mine cut diamond unique with its own personality.
Some confusion surrounds the term “old mine cut,” especially as the term has evolved over the years. It probably came into common use around the late 1800s, at a time when diamond production from Africa began to eclipse production from the “old mines” of Brazil and even older mines of India. “Old mine cut,” originally meant any “brilliant,” cut squarish shape, colourless or near-colourless diamonds that originated in Brazil or India. Then, as African mines began producing diamonds of higher colour quality, the term old mine cut was applied to any diamond with exceptional colour and one that had the older style cut. Eventually, old mine cut was applied only to squarish-shaped diamonds with faceting arrangements that were popular beginning in the early 1700s.
What to Look for in an Old Mine Cut Diamond
- Light affects a diamond’s appearance, so be sure to view the diamond under different conditions.
2. Expect to see a different contrast pattern (the pattern of white and dark areas caused by reflections within the diamond), as compared to modern diamond cuts.
3. Expect to see a difference in fire (breaking of light into spectral or rainbow colours): since the facets are larger, you should notice larger, more striking patches of colour (particularly under spotlighting).
4. Because original older cuts may have exceptionally thin girdles, be sure that the girdle is fully protected all the way around the diamond, leaving no edge exposed.
Article credit: GIA