Gems of Sri Lanka

Considered to be the most valuable gemstone variety in the Corundum mineral species, the distinct red in Ruby is caused by the presence of chromium. The colour spectrum of Rubies found across the world varies from orange-red to purplish red. Colour is the most significant factor affecting a ruby’s value: Fine gems are a pure, vibrant red to slightly purplish red.

Most Sri Lankan Ruby varieties are of a pinkish red and display a tint of purple, caused by the presence of iron in addition to chromium oxide, which is unique to its Sri Lankan origin. 

Although blue is the colour most widely identified with sapphires, the colour of sapphire can range from blue to violet, green, yellow, orange, pink, purple, and intermediate hues known as fancy sapphires.

Sri Lanka is the top source of finest Ceylon Sapphires to the global market and exports Ceylon Blue Sapphire, Padparadscha, star sapphires, and range of fancy sapphires to the global gem markets.

In addition to their ornamental purposes, sapphires are also used in purely functional applications, such as infrared optical components, high-durability windows, wristwatch crystals and movement bearings, and very thin electronic wafers, which are used as the insulating substrates of special-purpose solid-state electronics such as integrated circuits and GaN-based blue LEDs.

Abundant, attractive, affordable and colourful spinels are available in red, pink and blue colour and can occasionally exhibit asterism and chatoyancy. Spinel is a gemstone found in great abundance in Sri Lanka and until the rise of modern gemology in the 19th and 20th Century spinels were often mistakenly identified as Corundums, as they were mostly found in the same mine. Subsequent research into the mineral composition of these two gem families led to their separation and many gem enthusiasts finding that their beloved rubies and sapphires are in fact spinels.

Natural spinel, however, has always been a rare and beautiful gem. Sri Lanka is the second largest supplier of spinel to the global gem and jewellery market with colors ranging from ruby red, pink, orange, shades of reddish-brown, purple, blue, bluish-green, mauve, greenish-black, black to colourless. The occurrence of natural blue spinel colored by cobalt has been found in Sri Lanka.

Available in all the colors of the rainbow, Tourmaline also has a very complex mineral composition, which is the main reason behind their rich color composition. Gemstones from Sri Lanka belonging to the Tourmaline species differ from yellowish-green to bright green.

One of the most important gem Tourmalines found in Sri Lanka are mixtures of Dravite and Uvite. Often brown, yellowish-brown, reddish-brown, or nearly black in color, these species contain traces of vanadium, chromium, or both. When present in the right concentrations, these impurities produce rich green hues similar to tsavorite garnet.

While Uvite is rich in calcium, magnesium, and aluminium and Dravite is rich in sodium, magnesium, and aluminium; both forms within limestone that have been altered by heat and pressure and are fondly known as Savanna Tourmaline by gem dealers and merchants.

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Found in green-blue to blue colour variations, aquamarine crystals get the blue tone due to the presence of iron within the crystal. They are comparatively large and well-formed and the depth of sea blue color is most intense in large specimens while the color in smaller stones is comparatively lighter. Unlike other colored gemstones, aquamarine’s value comes primarily from its tone rather than the hue and saturation and stones with darker tone are highly-priced and sought after.

A variety of chrysoberyls displaying chatoyancy caused by the light reflecting from inclusions of tiny parallel needles or hollow tubes, cymophane are commonly known as cat’s eye.

Chrysoberyl occurs in varying degrees of transparency ranging from transparent and clear to cloudy translucent and opaque.

Fondly known as an ‘Emerald by Day and a Ruby by Night’, Alexandrite is a type of Chrysoberyl that is rare yet abundantly found in Sri Lanka. Their ability to shift colors from red to green when viewed under different light sources makes Alexandrite a highly sought after gemstone in the global market. A strongly pleochroic gem, which displays different colors when viewed from different directions, the three pleochroic colors of Alexandrite are green, orange, and purple-red.

However, the gem's color change doesn’t arise from the gem’s pleochroism, but from the mineral’s unusual light-absorbing properties. Although most Alexandrites found in Sri Lanka can be faceted, there is an occasional occurrence of colour changing alexandrite cat’s eye.

Gemstones belonging to the family of Garnet occur in a multitude of colours except for blue and are available in several varieties including almandine, andradite, grossular, pyrope, spessartine and uvarovite. With the exception of andradite and uvarovite, all the other types of Garnets are available in Sri Lanka, with some displaying asterism, chatoyancy and a colour change when viewed under different types of lighting.

All garnets have essentially the same crystal structure, but they vary in chemical composition. There are more than twenty garnet categories

A popular substitute for diamond around the world, Zircon is colorless in its chemically purest form.  Colorless zircon found in Sri Lanka is celebrated for its brilliance and flashes of multicolored light, called fire. Meanwhile, zircon is also typically found in an array of colors from brown, red, blue, purple, and rarely green. Often confused by cubic zirconia, Zircon has high brilliance and dispersion.

A versatile species of gemstones, Topazes are available in a variety of colors and colorless forms. Often identified by the hue name, such as pink or blue topaz, some of the most expensive and rare topaz have commercial names given to them. The high values red and pink stones are known as Imperial Topaz while the terms Precious Topaz or Sherry Topaz refers to stones with a rich yellow to a medium, peachy orange color.

A purple variety of the mineral quartz, the finest amethyst colour is strong reddish-purple to purple with no visible colour zoning. Coloured by Iron, the shades of Amethyst occur in transparent pastel roses to deep purples. Like many other gemstones, the quality of Amethyst varies according to its source. The best varieties of amethyst can be found in Siberia, Sri Lanka, Brazil and the far East.

A delicate pink version of the mineral quartz, Rose Quartz features shades varying from very light to medium-dark pink. Always found in massive form sans the regular, flat crystal faces Rose Quartz is typically found in pegmatites, but also occurs in hydrothermal veins and owes its delicate pink colour to microscopic inclusions of aligned silicate mineral fibres. Sri Lanka is a leading source for fine quality rose quartz rocks.