To start our feature on different types of gemstones, we will start with the best and most well known gemstone of them all the diamond. The diamond is the ultimate gemstone. It has very few weaknesses and many strengths. It sparkles with its extraordinary value and sentimental value. It is used in wedding rings to represent endless love or used as gifts/jewelry to be given to loved ones. But the diamond hk is so much more than its eternal beauty.
The diamond derives its name from the Greek work adamas meaning unbeatable. In hardness, there is no comparison. The diamond rates in the Mohs scale a 10 which is the hardest substance on Earth. Its cutting resistance is 140 times that of the ruby and sapphire, the gemstones(Corundum) that are next in the Mohs scale in hardness. The diamond’s optical properties such as luster and rigidness make it unique and easily distinguished from other imitations. Enjoy!
*History of Diamonds
The first recorded diamond dates back around 800 B.C. in India. Some believe it even dated back 6,000 years ago. The diamonds were used as decorative purposes and also as talismans to ward off evil and provide protection in battle. During the Dark Ages, diamonds were even stated to be used as a medical aid. Religious doctors even told patients that if they hold a diamond in a hand and make the sign of the cross would, it would cure and illness and heal wounds.
Diamonds became more popular during the 19th century due to discovery of diamond deposits in South Africa. This discovery leads to increased supply, improved cutting and polishing techniques, and growth in economy. In 1979, geologists found the Argyle pipe in Australia which to this date is the richest diamond deposit in the world. Argyle, since then, alone is responsible for supplying over one third of the world’s diamonds every year.
*Diamonds: How are they formed?
Diamonds consists of an allotrope of carbons that are formed in high-pressure, high-temperature conditions. Diamonds are produced 90 miles under the Earth’s surface at temperatures of about 2200 degrees Fahrenheit. Diamonds are formed deep within the earth and eventually, over extremely long periods of time, push their way to the earth’s surface, usually through volcanic eruptions.
The age of these diamonds from beneath the surface of the earth are from 1 to 3.3 billion years old! When diamonds are formed and begin their ascent to the earth’s surface, they go through channels where the magma from the volcano rises to the surface, picking up diamonds along the way and eventually depositing them on the surface, where they are eventually found and mined.
*The 4 C’s of Diamonds
There are four distinct characteristics that determine the value and quality of a diamond. These are the color, cut, clarity and carat. Otherwise known as the 4 C’s of a diamond. In the following, we will talk about these features in detail.
In the last newsletter, we touch based on the color of gemstones as being the most important feature due to the fact that color is the most obvious feature. The perfect diamond should appear clear and colorless but this is not the case for all diamonds. Diamonds can come in any color of the rainbow most common color is a shade of yellow or brown. The Geological Institute of America(GIA) have devised a guideline to grade diamond color. This guideline consists of a lettering system that ranges from the alphabet D – Z. Please see below:
D E F
G H I J
K L M
Faintly tinted, can’t hardly be seen and usually yellow in color
N O P Q R
Lightly tinted, usually yellow. Can be seen with the naked eye
S T U V W X Y Z
Tinted, starts from yellow and progresses to brown
The cut a diamond is determined by the diamond’s proportion such as its shape, width and depth. The cut determines what is called the diamond’s “brilliance”. Even if the diamond itself has perfect color and clarity, with a poor cut the diamond will have a dull brilliance. This is because the cut determines how light travels within the diamond. The Gemological Institute of America has also devised a clarity grading system to rank diamond clarity. This grading system includes Flawless (Fl), Internally Flawless (IF), Very Very Slightly Included (VV1 or VV2), Very Slightly Included(VS1 or VS2), Slightly Included(SI1 or SI2), and Included(I1, I2, and I3). Although this system had been contributed to the diamond industry, it is not widely used. This is due to the fact that it took a lot of practice and training to integrate it.
The cut a diamond is determined by the diamond’s proportion such as its shape, width and depth. The cut determines what is called the diamond’s “brilliance”. Even if the diamond itself has perfect color and clarity, with a poor cut the diamond will have a dull brilliance. This is because the cut determines how light travels within the diamond.
There are 3 types of cuts that can determine the diamond’s brilliance. These are a shallow cut, a cut that is too deep and ideal cut. A shallow cut is a cut of a diamond that is too low, that light traveling through it is lost on the bottom of the stone and does not come back into sight. This cut makes a diamond appear lifeless and dull. A cut that is too deep is a cut that is too high, that light traveling through it escapes through the sides and darkens the stone. An ideal cut is a perfect cut on a diamond that reflects light to the top of the stone, giving it perfect brilliance.
As stated on the last newsletter, a single carat(ct) weighs about 200 milligrams or.2 grams. For smaller carat diamonds that weigh less than a carat, it is expressed as points (pt). Points are 1/100 of a carat. Carat weight of a diamond is important due to the fact that larger diamonds are rarer than smaller ones, so basically the larger the diamond the more expensive it is. There is no standard grading system or diagram that can show different carat weight. This is because there are so many variations of diamonds in shape and cut, which makes stones of similar weight, look different.
Since diamonds are the most valuable and rarest of all the gemstones, efforts have been made to duplicate or even enhance diamonds using less expensive alternatives. A lot of times, honest mistakes have been made and these alternatives or other gemstones such as spinel were sometimes confused with real diamonds. In some cases, some dishonest people try to sell these alternatives to misfortunate buyers in order to profit. Below we will discuss about these alternatives and ways to identify them.
Synthetic diamonds are diamonds that are grown manufactured in a laboratory. The first known cases of diamond synthesis were claimed to be documented between 1879 – 1928, but this was never confirmed. It wasn’t until the 1940’s where research began in the United States, Sweden, Soviet Union started researching. Synthetic diamonds are otherwise known as High Pressure High Temperature (HPHT) diamonds or Chemical Vapor Deposit (CVD) diamonds. The name of both these synthetic diamonds derives from the processes used to create them. Some of these synthetic diamonds could either have greater, lesser or similar characteristics than that of a diamond. Therefore, these synthetic diamonds are used for abrasives, cutting and polishing tools, and switches in power stations.
Simulants are non-diamond substances that are used to replicate the appearance and even the shape of a diamond. The most basic and well known simulant is cubic zirconia (CZ). CZ at plain sight can sparkle more than a diamond and also it is less dense, meaning that a 1 carat CZ will be much larger than a 1 carat diamond. Nowadays, a more popular simulant is moissanite, which has all the same characteristics of a diamond. These characteristics include hardness (Moissanite-9.25 and diamond-10 in Mohs scale), refractive index(Moissanite -2.65 and diamond -2.42) and dispersion (Moissanite-.104 and diamond-.044). This makes it hard to differentiate the two at plain sight and would often require testers to tell the difference. In the next section we will discuss how to identify moissanites and other imitations.
*Real or Fake?
An old method of identifying diamonds is to do a scratch test. This requires scratching a diamond with another diamond which is destructive and is rarely used nowadays. The best and most reliable way to test for diamonds is to use testers that use thermal conductivity. These testers consist of battery powered thermistors mounted with a retractable copper tip. This tester works by injecting the heat onto the tested stone and then the device measures the amount of heat that it conducts. However thermal conductivity testers works best to distinguish diamonds and its other simulants, it will not help distinguish lab created or synthetic stones. To be able to identify these, certain optical techniques are needed. Laboratories use techniques such as spectroscopy, microscopy and luminescence in order to determine a certain stones origin. The average person can use loupes and microscopes to distinguish synthetic stones. Natural diamonds usually have minor imperfections and flaws such as inclusions or some type of foreign material, which will not be found in synthetics.