Gemstones and Values

The white diamond is the only gemstone to have it's own grading system. This system was introduced to gemology in the 1950s by the Gemological Institute of America. Before this time, all gemstones were classified and graded using nothing but the naked eye, which might not have been as reliable. However, the new innovation meant that diamonds were graded on their clarity by using 10 x magnifications. However, to this day, all other gemstones, precious or semi-precious, are still classified using 20/20 vision from the naked eye.

The Four "C"s in Classification and Value

When grading a diamond, the mnemonic of the fours C’s is commonly used to help the potential buyers understand what goes in on during the grading system. The four C’s stand for carat, clarity, cut, and colour. (However, these C’s can also be adapted to help the layman understand the grading of all other gemstones, too.) When buying a diamond, it is the cut that determines its value first and fore mostly. Following this are aspects of clarity and colour. Obviously, these criteria differ when applying to other gemstones, or the beautiful colourless diamond. But if you’re buying a ‘regular’ diamond, take into account the following factors.

  1. Does it sparkle in the light? If the diamond is clear enough, it will break the light and fragment it into a rainbow. This is known as dispersion.
  2. Does it chop up that light into tiny flashing bits? This is known as scintillation.
  3. Does it convey all of the above clearly to the naked eye? This is known as brilliance.

Cutting the diamond should produce all of the above effects. Before a diamond is cut, it is in its roughest, crystalline appearance and it will do none of the above. Only with fashioning from an expert will it produce this splendour.

In other gemstones, especially those with a deep colour, it is the purity and the beauty of the colour itself that determines the gem’s level of quality. The colour itself also makes the stone more valuable. Secondly, it is the aspect of the clarity of the stone, closely followed by the cut, and then any remarkable aspect the stone may have, such as star effects (this is know in gemology as asteria).

Due to the nature of the classification of stones, along with what was and was not fashionable at the time, different cultures, and the changeable nature of the definitions, shaping exactly what constitutes as a precious or a semi-precious stone has always been troublesome.

Amongst all gemstones, the emerald, sapphires, ruby and diamond stand out from the other stones as the most precious. But two other kinds of stone are also considered by many to come under the heading of "precious". These are opal and pearl (which is actually not a gemstone at all). The amethyst was also considered by many to be a precious stone at one time, even in ancient Greek times. However, at some point in the nineteenth century, a great number of amethyst stones were discovered in Brazil, and so their rarity was no longer a factor. And even as late as the last century, another gemstone that was considered to be precious was aquamarine.

However, many different kinds of stones are used in the trade these days, and this distinction between precious and semi-precious is rarely officially made. Lots of types of gems are used in all kinds of jewellery, from affordable to expensive, depending on the current trend, supply of the stone, or jewellery designer. Despite this, it is still emerald, sapphires, rubies and diamonds which stand out from the other stones.

The prices you can pay for gemstones vary widely and more often that not is a fluctuating market, depending on the type of stone. Tanzanite is a stone whose price had been incredibly unstable, whereas the classic diamond has remained quite fixed. And, obviously, larger stones are often found to be more expensive than smaller ones, but sometimes this is not the case, depending on certain stones popularity. Prices can range from an excessive $50,000 for a three carat ‘perfect’ ruby, to a mere $1 per carat for an amethyst.