The continual exploitation of gemstone deposits, the development of contemporary mining technology, and the discovery of new sources have all resulted in the increased availability of an entire spectrum of gemstones. Diamonds are now sourced in quantity from African countries, Australia, Russia, and Canada, whereas they were once only found in India, Borneo, and Brazil.

Considering our choice of gemstones, today’s jewelers have to know a great deal about colors and sources of gemstones. The value and popularity of stones are determined by fashion, quality, and availability. Independent gemstone dealers, wholesalers, large retailers, auction houses, small stores, and markets are all important sources of jewelers’ materials. Needs and experience will decide which source is the most appropriate. Finding two matching gemstones for a pair of earrings, or finding several for a ring, could pose many difficulties. Gem variety or individual features such as color, size, and shape will come into question. Identification and certification by a gem laboratory is another option.

Gemstone dealers can be asked to source gemstones of a specific size or type in order to satisfy a customer’s request for a particular design. Some dealers specialize in knowledge of a particular area of the world known for production of a particular gemstone type. A buyer of rubies or sapphires may often deal with Thailand and Sri Lanka. Another buyer might only do business in Africa, in search of colored gemstones. Many dealers have a broader range, without the limitation of a specialty.

The source of a gemstone is no longer necessarily the determining factor in a stone’s color. Heat treatments and irradiation are commonly used to alter and enhance color. This allows marketable gemstones to be mined from sources once believed to be inferior. An ordinary ruby can now compete with the famous ‘pigeon’s blood’ red rubies of Myanmar (Burma), or the Sri Lankan cornflower-blue sapphires (Ceylon sapphires).

Nature’s forces continuously create a bedazzling array of gemstones of every shape, color, and crystalline structure. The jeweller enhances each form and gives it new life. Modern technology allows a broad range of jewelry creations, now more than ever.

Rocks wear down after their initial formation due to weathering, erosion, and sedimentation. After rocks have undergone these processes, new rocks can be formed from their remains, continuing the cycle. Gemstones are found in rock where they have formed (in situ) or in sediments and deposits, like river gravels, which were created by rock weathering and erosion. River bends (alluvial), coastal sands (coastal) and seabeds (marine) are the homes of deposited diamonds and other gemstones, carried to their arrival by rivers and streams.

Geologists find gemstones in three groups: igneous, sedimentary, and metamorphic. The way a gemstone has formed determines the division into which it falls. The rock cycle is comprised of a continuous cycle of events, which form the three rock types.

Igneous rock is named after the burning red volcanic lavas that cool to form it. The Latin word ignis means fire. Rocks created from magma (molten rock) can take millions of years to form. The magma gradually cools beneath the earth’s surface as it rises. Crystals form within the magma as it cools and eventually solidify. All the while, temperatures and pressures change. When the cooling is slower, larger crystals form. Rocks like granite, formed by this process, are called intrusive igneous rocks, form inside the earth.

Pegmatites are intrusive igneous rocks. Pegmatites are created during the final stages of crystallization, and often form huge crystals with a wider variety of gemstones that any other type of rock. Minas Gerais (Brazil) is the most famous pegmatite region. Found there are tourmaline, topaz, aquamarine and morganite. The Pala area of California, the Nuristan area of northeast Afghanistan, the Alta mountains of northwest China, and the Yekaterinburg region of Russia are all important pegmatite areas. Mineral-rich fluids concentrated within cracks and fissures can cool to form amethyst, topaz, emerald, and benitoite.

Igneous rocks can also form when magma reaches the surface as volcanoes and fissures erupt, producing lava and ash. Some examples of crystallized volcanic rock that are considered extrusive igneous rock are: olivine basalt (which contains peridot), zircon, ruby, sapphire, moonstone, topaz, and the rare bixbite (red beryl).

Sedimentary rocks are created by weathering, erosion, and deposition of other rocks, and the evaporation, cooling, or transportation of fluids rich in minerals. Turquoise, malachite, rhodochrosite, amethyst and agate are all gemstones formed by sedimentary processes. Opal is formed from a silica gel.

Metamorphic rocks are formed when rocks are altered by temperature or pressure, giving birth to new minerals and crystals. Metamorphic rocks may be associated with large mountain-building processes or with smaller events like folding or faulting. The Indian subcontinent and Asia collided over 65 million years ago, forming the rubies of Myanmar. This pushed up the Himalayas, the highest mountain range in the world. Metamorphic rocks, and river boulders and pebbles contain Jadeite.