Colored Gemstones

Ruby

Famous for their beguiling shades of red, rubies come in light and velvety crimson tones with pink and purple overtones. Incredibly precious and rare are ‘pigeon blood’ red rubies. Pigeon blood rubies denote a brilliant pure red shade with no overtones of orange or brown. Today’s majority of significant ruby deposits are located on two continents: Asia and Africa. Asia is host to the earlier known ruby deposits, such as those in Myanmar (former Burma). High-quality rubies from Myanmar are mainly known for their desirable pigeon blood color. These rubies are officially recognized as the finest and most valuable gemstones.

Emerald

Coveted for their classic deep bluish-green to an almost velvety, grassy yellowish-green color, Colombian emeralds are the most famous– and typically the most expensive.Inclusions are a distinctive feature of emeralds, often being the iconic 3-phase inclusion (liquid, gas bubble, crystal trapped inside the stones). Most emeralds are highly included, with cleavages often reaching the surface. Therefore, their toughness is classified as generally poor (hardness of 7.5–8 on the Mohs scale) and oil treatments are common to improve the gemstones appearance/transparency.

Tourmaline

Tourmaline, a semi-precious stone, comes in a wide variety of colors and hues, with some being rarer than others. There are many reasons for the different colors in Tourmaline gemstones. It’s generally agreed that traces of iron, and possibly titanium, induce green and blue colors. Manganese produces reds and pinks, and maybe yellows. Some pink and yellow tourmalines might owe their hues to color centers caused by radiation, which can be natural, or laboratory-induced. The most commonly found colors are pink and green though other colors are not uncommon (such as blue, brown, orange and purple).

Tanzanite

Found in just one place on earth, tanzanite is a relatively recent discovery. Because the crystals show different colors depending on the viewing direction, cutters can fashion gems with a range of colors from purplish-blue to bluish violet depending on how much weight they want to retain from the rough.

The stone is almost always heat-treated to alter its color, which is originally more brownish. Such treatment is accepted in the industry and retail market and is therefore rarely mentioned to the buyer.

Amethyst

Amethyst belongs to the mineral Quartz and is one of the most famous crystals due to its beautiful color and tone but also its spiritual significance. Although the gemstone comes in a wide range of colors, the color is usually vivid purple. At one time, the gem was as expensive as rubies and emeralds). However, since the discovery of extensive deposits in locations such as Brazil, it has lost most of its value.When purchasing an amethyst piece, keep in mind that the stone is slightly sensitive to heat and intense light. Hence, it would help if you avoided strong sunlight, as this may cause the color to fade.When exposed to heat-treatment, the color changes to a transparent orangy yellow, a gemstone known as Citrine or light green, Prasiolite.

Aquamarine

Aquamarine belongs to the mineral Beryl, the same as emerald and morganite. The gem often features a pale light blue color but can also have a darker color and greenish tone. The stone is usually treated with heat (giving it a more bluish appearance), an accepted treatment stable for the stone.The stones are generally large and due to their softness and thus not suitable for everyday jewelry. However, these gems are perfect for cocktail rings and evening pieces. Professional cleaning of aquamarine jewelry is preferred as the stone is sensitive to heat and ultrasonic cleaning.

Garnet

From a gemological standpoint, the classification of garnet is the most complex of all gemstone groups and species. Garnets are found in many colors, including red, pink (rhodolite), green (tsavorite, demantoid) and orange (spessartite).For the person interested in jewelry and gemology, Garnets may feature some intriguing and unique inclusions, such as ‘Horsetail’ in Demantoid Garnets and ‘Heatwave’ inclusions in Hessonite Garnets. They are stable to light and chemicals, but you should always visit your jeweler when cleaning Garnet jewelry.

Opal

Opals, which can be both transparent and opaque, are the most popular phenomenal gem. Most Opals found today were formed some 15-30 million years ago in desert areas with intense seasonable rainfalls and in rocks rich in silica. During the winter, heavy rains raise the water table inside the rocks. The rainwater carries down the silica insoluble, which fills the cavities and fractures within the stone. In the summertime, the sun dries out the area and the water table retreats farther underground. As the water evaporates, the gem opals can form in the cracks and cavities. Because of its amorphous character, it is classed as a mineraloid, unlike crystalline forms of silica, which are classed as minerals. Opals should be kept by themselves in soft cotton to prevent marring by other items in your jewelry box. Some rare types of opals, like Tintenbar Opals, should be kept in water to avoid cracking.