Ruby is one of the three precious coloured gemstones, and part of the family of corundum, where the predominantly red stones are Rubies whereas the rest of the colours are all considered Sapphires. Ruby is the birthstone of July, named after Latin word ‘ruber’, which means red. Ruby is the most valuable coloured stone, often found in smaller sizes as compared with Sapphires, even 1 ct sized stones holds considerable value.
History & Lore
Historically, Rubies has always been confused with Spinels. In fact, some famous ‘Rubies’ such as the Black Prince Ruby is actually a Spinel. Corundum is a naturally colourless material, but may have different colours when impurities are present.
The largest Ruby in the world is the 125 West Ruby, this Ruby rough weighs at an incredible 18,696 cts. The 125 West Ruby is of semi-opaque to opaque material, this makes it more suitable for carving than to be faceted. there are some speculations that it may produce a Star Ruby when cut into a cabochon, but nobody knows the exact outcome.
One of the largest faceted Rubies and possibly the most famous, is the Sunrise Ruby. Weighing at an outstanding 25.59 cts, the Burmese Ruby fetched more than USD$ 30 million, which averages out to over US$1 million per carat. This is the most expensive coloured stone ever auctioned, it is also the highest recorded price per carat for any coloured stone and the most expensive piece by Cartier that is ever sold in an auction. To put it into perspective, a D colour Flawless clarity Diamond at 88 cts sold for USD$14 million, that puts a per carat price of the diamond at about only 14% of what the Sunrise Ruby achieved. The Sunrise Ruby is this expensive because it comes from the most prestigious mine for Ruby, the Mogok mine, it is also unheated and comes with good clarity and the best colour for Ruby, the Pigeon’s Blood Ruby.
In our inventory, we feature many investment grade Rubies, that are of Pigeon Blood colour, Unheated Burmese Origin with good clarity.
Ruby ranges from pinkish-red to purplish-red to orangy-red to brownish-red. Colour is the most important price factor for Rubies. The most desired colour in Ruby is known as the Pigeon’s Blood colour, which is the colour of the eyes of a white pigeon, unlike what the name suggests. Depending on grading systems of different laboratories, Pigeons Blood Ruby can have just a very slight hue of purple. For the trade term Pigeons blood, the most accredited laboratories for coloured stones, SSEF and Gubelin, now shares the same standards of grading with each other.
Rubies that have a Pigeon’s Blood colour grading are often sold at a premium over other Rubies, and the difference can be folds of the normal Ruby price. Rubies of a lower colour saturation trades at prices far below that of a Ruby with more vivid saturations. Some laboratories use different terms for Rubies, such as Royal Red, which are used to describe darker purer red. Pink Rubies can be considered Rubies or Pink Sapphires depending on laboratory and country, the line between them is very fine.
Rubies typically have visible inclusions and are not as clean as Sapphires. An eye clean Ruby would be considered top grade in terms of clarity. These Rubies often command a much higher premium over similar coloured Rubies with eye visible inclusions. Of course, eye clean rubies are our first recommendation, but due to its rarity and price, it is more acceptable for Rubies to be slightly included with some eye visible inclusions than other gemstones.
Typical clarity characteristics include thin mineral inclusions called needles. Rutile needles, or “silk,” can sometimes contribute positively to a gem’s appearance.
Rubies are often faceted into oval shapes due to its crystal shape and gem cutters trying to preserve as much weight as possible. This also causes the Ruby to be either too shallow or too deep, which is another major consideration when making a purchase. Stones too shallow will create an obvious window, too deep, you will be paying for the extra weight.
Rubies comes from many origins, these include Myanmar (Burma), Sri Lanka, Thailand, Cambodia, Africa, Afghanistan, Nepal and Vietnam. Of these origins, the current most important ones that holds considerable market shares are Burmese Rubies and African Rubies, mainly those coming from Mozambique. The most famous Rubies, those from Himalayas(Nepal), Burma, and Northern Vietnam, are typically formed in marble, which has lower iron content, producing stones that frequently comes in an intense red colour. Rubies from other origins, are generally higher in iron content, so such stones are darker in appearance.
Burmese Rubies are mostly from the two major mines in Mogok and Mong Hsu. Mogok Rubies have been historically known to produce the finest Rubies in the world, holding colour in every lighting condition, which makes them the most sought after and valuable origin of Rubies. Mogok Ruby rough also normally produces well-proportioned gemstones. Mong Hsu rubies mostly have a dark core by nature, which has to be removed by high temperature heating. Rubies without such cores and does not need to be heated represents a very small portion of Mong Hsu productions.
Sri Lankan Rubies are mostly towards pink in colour, though limited amount of top-quality stones can rival Burmese produced Rubies. Sri Lankan Rubies are commonly cut into an overly deep shape due to the rough shape.
Thailand and Cambodia Rubies actually comes from the same deposit that is split by the two countries borders; they mostly have a garnet-red colour but often comes with good clarity. In the trade, Thai Rubies is a common term for fracture-filled Rubies. However, this is independent of Rubies originating from Thailand.
Though also available in Madagascar, Tanzania and Kenya, the representative of African Rubies are those of Mozambique origin. Mozambique Rubies are generally darker than Burmese, but fine pieces can rival the Mogok Rubies, they also have better clarity and produces slightly bigger stones. As of now, Mozambique rubies are probably the most important and widely appreciated source, after Burmese, with prices increasing over the years.
Afghanistan and Vietnam do produce some Rubies of comparable quality to Mogok, but very few due to low supply of Afghanistan and low clarity in Vietnam Rubies. Nepalese Rubies can rival Mogok Rubies in colour, but they are mostly low to mid commercial quality in terms of clarity. Rubies of 5 cts or less often have heavy colour zoning.
Rubies can exhibit asterism, which is also known as the star effect. Most of the Rubies with such effect comes from Sri Lanka or Burma, with Mogok origin producing the finest Star Rubies. Stones with distinct six rays are highly sought after and valuable, the more defined, the higher the price. The ‘Raviratna Star Ruby’ is the largest star ruby in the world, weighing a whopping 3553 cts, with a perfect six ray star and valued at USD$500 million by some experts.
Majority of the Rubies on the market are heated, and it is so common that heated Rubies are widely accepted in the industry. Rubies are heated to improve its colour and clarity, as well as removing dark cores or improving the effect of Star Rubies. Heated Rubies are easily identified by experienced gemmologists due to the high heat damaging or healing some of the inclusions in the stone. Unheated Rubies are rare and generally go for much higher prices than their heated counterparts. Rubies on the market that are not specified to be unheated should be assumed to be heated Rubies.
Heat treatment is also graded, with heat only being the best, graded on a scale of H,H(a),H(b),H(c),H(d),H(Be) and HPHT, by renowned gem laboratory GRS. H to H(d) is a grading of how much residue of glass is present in the Ruby, as a sign of clarity enhancement, with H being none and H(d) being known as composite Ruby with significant residues. H(Be) means that the Ruby has been treated with beryllium to artificially change its colour, such treatments are not widely accepted in the industry. HPHT means that the Ruby has gone through not only high heat but high pressure as well, which is usually done to introduce stronger colours into the Ruby.
Lower quality material may have surface-reaching fractures filled with a glass to decrease their visibility and make the gem more transparent. H(d) rubies are also known as lead filled rubies, these stones are one of the newer treatment methods and sells on the market for only couple dollars per carat. This also the reason why we recommend that when purchasing Rubies, always buy those with certifications from reputable laboratories and only purchase H, H(a) or H(b) Rubies.
Synthetic Rubies, just like synthetic Sapphires, are widely available in the market, both as jewellery and for commercial usage. The first laser is actually fired using a synthetic Ruby rod. Synthetic Rubies can be produced in many different ways such as hydrothermal, flame fusion and more. Flame fusion remains the most common method of producing Synthetic Rubies due to the low cost of it. It requires an experienced gemmologist to separate synthetic Rubies from naturals, so always buy either from reputable dealers or those certified from reputable laboratories.
Rubies are one of the hardest gemstones in the world, just after Diamonds and after man-made Moissanites. Rubies also has very good toughness and have no cleavage planes, which means that it is less likely to break when hit. However, as Rubies tend to be more included, included stones with many fractures are easier to break. With a Mohs scale rating of 9, Rubies are durable jewellery suitable for everyday wear, including in rings or bracelets, and designs that are more susceptible to scratches, these are all also subjected to the quality of the Ruby itself. Rubies should be cleaned with warm soapy water and a soft brush.