Diamond Cutting History
Diamonds have been prized since humans first found deposits in the 4th century and traded them along the infamous silk road. When our ancestors first found these sparkling rocks they knew they had found something special, but it would take years of research and understanding to get these billion year old crystals to the modern brilliant cut diamond we see in our heirlooms today.
Diamonds are prized for several reasons: beauty, rarity, and durability. In fact, diamonds are one of the hardest natural materials in the world, with strong giant covalent bonds that make the stone an almost impenetrable fortress, perfect to wear every day, but not so easy to cut and mould. Needless to say, when we first tried to cut diamonds we didn’t have much luck, usually just lightly polishing the natural crystal opposed to faceting it to create a new shape. However, centuries on and the understanding of the chemical composition and atomic structure of diamonds meant that by the beginning of the 18th century we were starting to see diamonds resemble the stones we know today. However, today, I want to shed the spotlight on one very special diamond cut in particular, the old mined cut.
To the left is an old cut diamond and emerald ring, centre a modern brilliant cut marquise diamond and right a transitional cut diamond target ring c.1920
The Old Mined Cut
Old mined cut diamonds were the modern brilliant cut of the early 1700s. A true testament in innovation, these hand cut stones were the pinnacle of advancement in the trade, with new understandings that allowed master diamond manufacturers to unlock the unique adamantine lustre and fire of the diamond.
These antique stones were exclusively cut by hand and followed the natural shape of the diamond crystal (see example below). Due to them being hand manufactured the stones have a lot of character to them, with proportions that are often slightly ‘off’; indeed, it is uncommon to see a true antique stone where the culet is perfectly centred and the crown even on both sides, but this is part of their unique charm.
A natural diamond octahedron crystal, source GIA website
Behind the name
The name old mined cut originally comes from the provenance of the diamond. In the 18th century the main diamond deposits were Brazil and India, you may have heard of the infamous Golconda mines. These ancient diamond mines produced large, but often lower coloured diamonds, due to the mineral deposits found in their soil. However, by 1860 a large new deposit of diamonds of diamonds were located in South Africa, which began to take over the global market from the “old mines” of Brazil and India. So originally the old mined cut referred to diamonds sourced and cut from the “old mines”, however over time it has evolved to mean any diamond cut with the characteristics of an old mined cut.
The kingdom of Golconda on an antique map
Old Mined Cut Characteristics
The most well-known feature of an old mined cut diamond is its open culet. This is a result of the diamond manufacturer adding an extra facet to the very bottom of the diamond, which can be seen through the table as you look down onto the stone, giving it the classic ‘fisheye’ look. However, the other characteristics of an old mined cut diamond are: a high crown, small table, 58 facets and a rough square shaped outline, as well as the diamonds typically being lower in colour because of their origin.
An old mined cut diamond ring from our sold archives
What is a transitional cut diamond?
Where things get confusing between the true old mined cut and the modern day brilliant cut is the transitional cut (still with me?). The transitional cut diamond is so named because it forms the bride between the old mined cut diamond and the modern brilliant cut diamond. In 1874 There was an introduction of a bruting machine, which allowed diamonds to be cut with much higher precision, leading to a more rounded outline to the stone opposed to that square shape. This also resulted in the table of the stones lowering and the culet of the diamond becoming smaller; so if you see an antique cut stone that is of a higher colour and rounder shape you are most likely looking at a diamond cut post 1874, which is a great marker for antiques dealers estimating the age of a piece.
A transitional cut diamond ring, from our sold archives
Why buy an old mined cut
Old mined cut diamonds remain incredibly popular for a number for reasons. Firstly, their character. The hand cut nature of the stones gives a more organic and personal feel, with each diamond being a true one off, which gets rid of that ‘cookie cutter’ look of a mass produced, modern brilliant cut, engagement ring.
Secondly, their fire is unparalleled. Old mined cut stones have chunkier facets, which split and disperse light in larger areas, giving you larger rainbows coming from the stone when you turn it. Modern brilliant cuts are cut instead for brilliance, as the name suggests, which is the return of white light to your eye opposed to fire, which is the splitting of white light into is full rainbow of colours. As a result you will likely get a more lively looking stone.
Thirdly, there is the environmental aspect of buying an antique. Diamonds are incredibly valuable and durable, which means they often outlive their caretakers, and get recycled and sometimes even re-cut into more popular cuts. This means that buying an antique stone you don’t need to be as concerned with social and environmental impact as you would with a newly mined diamond.
Lastly, an old mined cut diamond is likely to be cheaper: you heard us right. Because they are antique, they are exempt from VAT, and often are found in antique pieces for a lot less than a modern stone. With all of that added up, we know you are going to be as obsessed with this gorgeous cut as we are.
An old mined cut diamond cross ring from our sold archives