History and Lore
The Romans believed that diamonds brought courage and bravery during battle. Jewish high priests used diamonds to decide the innocence or guilt of the accused: A stone held before a guilty person dulled and darkened; a stone held before an innocent person glowed with increased brilliance.
TheHindus believed that this brilliant gem was created when bolts oflightning struck rocks. To be effective as a talisman, the gem wouldhave to be given as a token of love or friendship. If bought orsold, it would lose its powers. April’s birthstone, diamond is saidto be at its most potent when set in steel. Of course today’s diamondsare set in gold or platinum.
DIAMONDFACT: THE LARGEST ROUGH DIAMOND EVER FOUND IN THE WORLD IS THE CULLINANDIAMOND FROM SOUTH AFRICA: 3,106 CARATS
Asymbol of innocence, justice, faith and strength, the diamond wasbelieved to make its wearers courageous and victorious over theirenemies. When set in gold and worn on the left side, it held thepower to drive away nightmares and soothe savage beasts. Diamondswere even thought to be so powerful that they could stop lechery.
A diamond’s trip from the mine to becoming a beautiful, polishedgem has several steps, all of which must be executed with exactingcare and attention to detail. We’ve put together an overview ofsome of the important steps, to give you an idea of where diamondscome from and how they become the brilliant and awe-inspiring gemsthat have been valued for centuries.
More than 250 tons of ore need to be mined to yield a one-caratrough diamond. However, only about 20% of all rough diamonds aresuitable for use as gems. Since diamond is the hardest materialknown to man, the rest of the diamonds are used for industrial purposes,such as cutting, boring and grinding.
are mined in the deepest area of Kimberlite Magma pipes (up to 75miles deep) called “blue rock” or “blue ground”, as well as in theshallower area 50 to 60 feet below the earth’s surface called “yellowground.” Diamonds may be buried for thousands of years before beingexcavated from blue rock, or they may be released through the processof erosion and re-deposited in alluvium, forming alluvial (riverside)deposits. Today, more than 95% of the world’s diamond supply ismined in South Africa. However, diamonds are also mined in Australia,South America, Russia and Canada.
DIAMONDFACT: THE TYPICAL BRILLIANT-CUT DIAMOND HAS 58 FACETS; 33 ON THECROWN (TOP) AND 25 ON THE PAVILION (BOTTOM).
The first step in the diamond making process, marking is done afterexamining each rough diamond to decide how it should be cut to yieldthe greatest value. The shape of the rough diamond and the numberand location of inclusions, or blemishes, are first considered.Since the crystalline structure of diamond causes it to have a grain(called cleavage), it is critical to plan for the facets of thediamond to be made in the correct direction. Taking these factorsinto account, the planner decides how the diamond should be cutand marks it to indicate where the stone should be cleaved or sawed.
After a diamond is marked it is sent to a cleaver or a sawyer, dependingon the stone. When the stone is very large and valuable, cleavingit is a critical process, because a mistake by the planner or thecleaver can shatter the diamond. The cleaver’s job is to cut thediamond into two pieces to bring out the best angles and establishwhat the final cut will be. Cleaving is performed by striking thestone with a sharp blow from a blade or hammer. However, some stoneshave too many stress points and might fragment if cleaved, so theymust go to the sawyer. This process is extremely meticulous andtime-consuming.
DIAMONDFACT: DIAMONDS ARE THE HARDEST SUBSTANCE ON EARTH, BUT BECAUSE THEYHAVE GRAIN, THEY CAN BE CHIPPED IF STRUCK.
The saw used in diamond processing is a paper-thin disk of phosphorbronze that rotates on a horizontal spindle at about 4,000 rpm.The diamond is clamped so it rests against the blade and is sawedfor several hours, depending on the size of the diamond. Since diamondis the hardest substance on earth, it can only be cut by anotherdiamond. Therefore, diamond dust is used on the saw, as well asthe actual diamond dust generated by the crystal being cut.
The next step in cutting a round stone is called girdling, or rounding.The diamond is placed in a lathe and a second diamond is held againstit using a long handle, which slowly rounds it into a cone shape.The next step is for the stone to go to the blocker, who specializesin placing the first 18 main facets on a brilliant-cut diamond.It then goes to the brillianteer, who places and polishes the remaining40 facets (if the stone is being cut in the standard 58-facet brilliantcut).
The last step in the diamond finishing process is polishing. Thediamond is clamped onto a revolving cast-iron lap (a horizontal,circular disk) that has been charged with diamond dust. The finediamond dust acts as an abrasive to polish away small imperfectionsand make the surface of the stone perfectly smooth.