Suzi has undertaken extensive studies into coloured gemstones and diamonds. She is a qualified gemmologist and member of The Gemmological Association of Australia (GAA) and The Gemmological Institute of America (GIA).

Purchasing a gemstone can be a daunting experience; rapid advances in technology and a lack of technical understanding can often leave people feeling overwhelmed and unsure about what to buy or where to buy it from. We encourage you to contact us if you are uncertain or curious about a particular stone. Suzi is happy to help and very much enjoys discussing the subject with her customers. Suzi can also show you particular stones you may be interested in to help make the decision easier as photos may not capture the true colour and beauty of a gem.

Carat

While carat is a measurement of purity for gold (see metals), for diamonds and other gemstones, it is a measurement of weight. One carat is equal to 200 milligrams.

The larger the stone, the more mass it contains and the heavier it will be. As the carat size of a stone increases, so does its price. But there is another factor apart from size which influences price: rarity. Approximately one in one million mined rough diamonds are large enough to produce a finished one carat stone, much less are capable of producing a two carat stone and even less a three carat stone. At the time of writing, a two carat diamond is approximately 4 times the price of a one carat diamond and a three carat diamond is approximately nine times the price of a one carat diamond.

It is important to remember that two stones of equal carat may have differing diameters depending on how they have been cut, resulting in one stone appearing to be larger than the other even though their mass is the same.

Treatments and Enhancements

Gemstone enhancement is a treatment process other than cutting and polishing that improves the appearance (color and clarity), durability, availability and, consequently, value of a gemstone. Treatment includes heating, oiling, irradiation, waxing, dying, bleaching, etc.

There are many ways to enhance the appearance and durability of gemstones. Some of these enhancements are permanent while others are temporary. Gemstone enhancement has become such a common and accepted practice that experts believe the vast majority of stones are now treated in some way.

Synthetics

A synthetic gemstone shares a natural stone's physical, chemical and optical qualities but is created in a laboratory instead of occuring naturally. Some modern, synthetic gemstones look so "natural" that they are difficult to detect, but an experienced gemologist can usually identify them. A natural stone will normally exhibit imperfections due to the environment in which it was created whereas a synthetic will not. Synthetic stones are much cheaper than natural stones.

Mohs Hardness Scale

One of the most important tests for identifying mineral specimens is the Mohs Hardness Test. This test compares the resistance of a mineral to being scratched by ten reference minerals. Friedrich Mohs, a German mineralogist, developed the test in 1812. He selected ten minerals of distinctly different hardness that ranged from the soft mineral talc to the very hard mineral diamond and arranged them on a scale of hardness (see table below). With the exception of diamond, the minerals are all relatively common and easy to obtain. The test is useful because most specimens of a given mineral are very close to the same hardness, which makes hardness a reliable diagnostic.

Diamond is the transparent, gemstone-quality, crystalline form of carbon and it is indeed the hardest known natural substance on earth. Diamonds are not only prized for their exceptional hardness but also for their brilliance and incredible fire. Although traditional colourless or white diamonds are by far the most popular, coloured diamonds such as yellow (champagne) and brown (cognac) are actually the most commonly occurring diamonds. Other "fancy" diamond colours include blue, pink, red, green, orange and black.

What is a conflict free diamond?

A conflict free diamond is one where the money used to purchase the diamond has not then gone on to fund war or the buying of weapons for war. Conflict free diamonds are not taken by force but have been bought fairly with respect for human rights.

Why is it important to buy a conflict free diamond?

As many of the world's diamonds come from places of present conflict, such as Angola, the Democratic Republic of the Congo, Sierra Leone and Liberia, it is an ethical imperative that the diamonds mined from these places have not funded war or have not contributed to fudes or fights for power. If people were to only buy 100% conflict free diamonds, then conflict diamonds (also known as blood diamonds) would become worthless as there would be no market for them.

What is the Kimberly Process?

The Kimberly Process is a set of rules and guidelines for the import and export of rough, uncut diamonds. It ensures that every shipment of diamonds that crosses the border of a participating country must be certified, numbered and sealed in tamper-resistant containers. When diamonds are shipped, containers are accompanied by government validation certificates in order to verify the diamonds have been purchased from legitimate sources who are not involved in funding conflict.

Ruby is the red variety of the mineral corundum (of which sapphire is also a variety), which is one of the hardest minerals on earth. The red colour of ruby results from a small a mixture of chromic oxide. Only red corundum is entitled to be called ruby, all other colours being classified as sapphires. The most prized tint is blood red or crimson, known commonly as "pigeon's blood".

For thousands of years, the ruby has been considered one of the most valuable gemstones on Earth. It has everything a precious stone should have: magnificent color, excellent hardness and outstanding brilliance. In addition to that, it is also an extremely rare gemstone. Transparent rubies of large size are even rarer than diamonds. The ruby is considered an excellent choice for the jewelry and is second only to the diamond for strength and durability. Although ruby is a tough and durable gem, it is still subject to chipping and fracture if handled incorrectly.

Sapphire is the name for all varieties of corundum except red, which is reserved for ruby. Because of this, the physical and chemical properties of the two stones are almost identical. Blue is the well known colour for sapphire but it is also found in green, orange, pink, gray, white, black, brown, and purple. Used on its own, the word sapphire referes to the blue stone, other varieties usually specify the colour in the name. These alternative sapphires are known as "fancy" in the gem trade.

Sapphires and rubies have been successfully and widely produced synthetically. In appearance, chemical composition and hardness, they are almost identical to the natural gems. France is the major production hub for synthetic corundum.

Although Sapphire is a hard and durable gem, it is still subject to chipping and fracture if handled carelessly.

Emerald is the most precious variety of the mineral beryl. The famous green color of emerald is unparalleled which helps to explain why it is one of the 'precious four' gemstones of the world (the others being sapphire, ruby and diamond).

Although it has excellent hardness (7.5-8 on the Mohs scale), most commercial emerald has minute, surface-reaching fractures and inclusions which make it susceptable to damage. Because of this, great care must be taken when wearing, storing and cleaning emerald jewellery.

Other Gemstones