Gemstone
A gemstone is a piece of mineral crystal used to make jewelry or other adornments. Webster Online Dictionary defines the term broadly enough to include certain rocks like lapis lazuli, opal, and obsidian. Organic materials such as amber, jet, and pearl also fall under this definition despite not being minerals. Most gemstones are hard, but softer minerals like brazilianite may be used for their color or luster. Soft minerals are generally avoided due to brittleness and lack of durability. The industry of colored gemstones currently stands at US$1.55 billion. This figure is projected to rise to $4.46 billion by 2033. A gem expert is known as a gemologist while a maker is called a lapidarist. Diamond cutters hold the specific title of diamantaire.
The traditional classification in the West traces back to ancient Greece with a distinction between precious and semi-precious stones. Modern use reserves the term precious for emerald, ruby, sapphire, and diamond. All four possess translucency, fine color, and hardness scores from 8 to 10 on the Mohs scale. Other stones rely on color, translucency, and hardness for classification. A green garnet called tsavorite can exceed the value of a mid-quality emerald. The terms precious and semi-precious are arguably misleading in commercial contexts. They suggest value differences that do not always reflect market reality. Up until the 19th century, bulk amethyst found in Brazil was considered a precious stone. Aquamarine, peridot, and cat's eye have been regarded as precious within the last century. Today the trade no longer makes such distinctions based solely on rarity or tradition.
Gemologists identify gems using technical terminology specific to their field. Chemical composition serves as the first characteristic for identification. Diamonds consist of carbon while sapphires and rubies contain aluminium oxide. Crystals classify into systems like cubic, trigonal, or monoclinic. Habit describes the form usually found in nature. Gemological Institute of America developed a grading system in the early 1950s. This system introduced 10x magnification as the standard for clarity assessment. Historically all gemstones were graded with the naked eye assuming 20/20 vision. Colored stones still often use this older method today. A mnemonic device known as the four Cs helps describe grading factors. Color, cut, clarity, and carats carry different weights depending on the stone type. In diamonds cut determines primary value followed by clarity and color. For colored stones purity and beauty of color remain the primary determinant. Emeralds will always possess a number of inclusions regardless of quality.
Most gemstones are cut and polished for usage as jewelry rather than used in crystal form. Two main classifications exist for these finished shapes. Stones cut as smooth dome-shaped objects are called cabochons or simply cab. These have been popular since ancient times and offer greater durability than faceted gems. Opaque or semi-opaque materials like opal, turquoise, and variscite commonly take this shape. Grinding wheels and polishing agents shape the smooth dome surface. Transparent gems normally receive facets to show interior optical properties. Facets reflect light perceived by the viewer as sparkle. Faceting machines hold the stone onto flat laps for cutting. Angles must be exact to maximize reflected light. If angles prove too steep or shallow light passes through without reflection. Rarely some cutters use special curved laps for curved facets. The faceting process requires precise calculation based on optical properties.
Gemstones often undergo treatment to enhance color or clarity before reaching consumers. Heat improves or spoils gemstone color depending on application. Most citrine results from heating amethyst while partial heating creates ametrine stones. Aquamarine frequently receives heat to remove yellow tones or deepen blue colors. Nearly all tanzanite is heated at low temperatures to eliminate brown undertones. A considerable portion of sapphire and ruby receives various heat treatments. Jewelry containing diamonds requires protection with boric acid during heating repairs. Sapphire and ruby should not be coated with boric acid as it etches surfaces. Irradiation processes create colors that do not exist in nature. Virtually all blue topaz has been irradiated to change white to blue. Health risks related to residual radioactivity have led to government regulations. Emeralds containing natural fissures sometimes receive wax or oil filling. This disguises flaws while improving apparent color and clarity. Turquoise also commonly undergoes similar fracture filling techniques.
The socio-economic dynamics of the gemstone industry shape livelihoods in developing countries. Many mines face challenges including inadequate safety measures and low wages. Miners endure hazardous working conditions for meager pay contributing to poverty cycles. Operations frequently occur in remote areas lacking infrastructure or essential services. Environmental degradation poses long-term threats to ecosystems and biodiversity. Unregulated mining causes deforestation, soil erosion, and water contamination. The lack of standardized certification undermines market integrity and trust. Middlemen and corporations capture disproportionate shares of profits along the supply chain. Unequal distribution fails to improve socio-economic inequalities in mining regions. Addressing these challenges requires intensive effort from governments and industry executives. Implementing regulations ensures fair labor practices and environmental sustainability. Investing in community development projects helps alleviate poverty among marginalized communities.
Synthetic gems differ physically from imitation stones yet remain chemically identical to natural varieties. Ruby was first synthesized by Auguste Verneuil using flame-fusion process in 1902. World production of corundum via this method reaches 1000 million carats annually. Flame fusion completes inside a Verneuil furnace producing an oxyhydrogen flame. Chemical powder passes through the flame melting ingredients onto a ceramic pedestal. For corundum the flame must reach 2000 degrees Celsius. Czochralski process developed by Jan Czochralski in 1918 uses crystal pulling methods. Flux growth begins with molten liquid flux dissolved in graphite or platinum crucibles. Hydrothermal growth imitates natural mineral formation under extreme pressure. Synthetic emerald became possible with flux growth development taking months to years. Gemstones created from flame fusion may contain small air bubbles trapped during formation. Visible banding appears from boule formation while chatter marks show surface damage. Inclusions from crucible use appear in flux melt process results. These characteristics allow gemologists to distinguish synthetic from natural stones.
Common questions
What is the definition of a gemstone according to Webster Online Dictionary?
A gemstone is defined as a piece of mineral crystal used to make jewelry or other adornments. This broad definition includes certain rocks like lapis lazuli, opal, and obsidian. Organic materials such as amber, jet, and pearl also fall under this classification despite not being minerals.
When was the Gemological Institute of America grading system developed?
The Gemological Institute of America developed its grading system in the early 1950s. This system introduced 10x magnification as the standard for clarity assessment. Historically all gemstones were graded with the naked eye assuming 20/20 vision before this development.
How much is the current value of the colored gemstone industry projected to be by 2033?
The industry of colored gemstones currently stands at US$1.55 billion. This figure is projected to rise to $4.46 billion by 2033. The growth reflects increasing market demand and valuation changes over time.
Who are the professionals called gemologists and lapidarists?
A gem expert is known as a gemologist while a maker is called a lapidarist. Diamond cutters hold the specific title of diamantaire. These titles distinguish between identification experts and those who physically shape stones.
What are the four main precious stones reserved for modern use in the West?
Modern use reserves the term precious for emerald, ruby, sapphire, and diamond. All four possess translucency, fine color, and hardness scores from 8 to 10 on the Mohs scale. Other stones rely on color, translucency, and hardness for classification instead.