Amethyst is the violet-to-purple variety of quartz (SiO2). Its color results from trace amounts of iron and natural irradiation. Amethyst is prized for its clarity and range of hues, from pale lavender to deep reddish purple. It is transparent to translucent and is commonly faceted or cut en cabochon for jewelry.

Amethyst is durable enough for daily wear. Clean with warm, soapy water; ultrasonic cleaners are usually safe, but avoid excessive heat and prolonged sunlight, which may cause fading.

Aquamarine is the blue to blue-green variety of beryl (Be3Al2Si6O18). Its color is due to trace amounts of iron, and stones range from pale blue to deep greenish blue. Aquamarine is highly transparent, has a vitreous luster, and is usually free of visible inclusions.

Major sources include Brazil (the world’s largest producer), Nigeria, Madagascar, Zambia, Pakistan, Mozambique, and the United States (notably Colorado and Wyoming).

Diamond is a crystalline form of pure carbon (C), renowned for its unmatched hardness and brilliant luster. It is the hardest natural material, rated at 10 on the Mohs scale, making it exceptionally durable for all types of jewelry.

While diamonds are often prized for their "colorless" appearance, perfectly colorless stones are rare. Most natural diamonds display a subtle range from colorless (D–F) to light yellow or brown. “Fancy color” diamonds also occur in rare hues such as blue, green, pink, orange, and even red, but these are highly unusual and extremely valuable.

Black diamonds are a polycrystalline variety of diamond, composed almost entirely of carbon (C). Their dark color is due to a dense concentration of microscopic inclusions—usually graphite, pyrite, or hematite—throughout the crystal, which gives them an opaque, black appearance. Black diamonds are found in both natural and treated forms, with most commercial stones treated to enhance color.

Lab grown diamonds are crystalline carbon gemstones produced in controlled laboratory conditions using either High Pressure High Temperature (HPHT) or Chemical Vapor Deposition (CVD) processes. Physically, chemically, and optically, they are identical to natural diamonds, with the same structure, brilliance, and hardness.

Emerald is the vibrant green to bluish-green variety of beryl (Be3Al2Si6O18), colored primarily by trace amounts of chromium and sometimes vanadium. Emeralds are prized for their saturated color, but most contain inclusions or surface fissures, commonly referred to as the stone’s “jardin.” Their relative softness and internal features mean care is required during setting and wear.

Major sources include Colombia (notably Muzo and Chivor), Zambia, Brazil, Zimbabwe, and Afghanistan. Most emeralds are cut in a rectangular step shape, known as the emerald cut, to enhance color and minimize stress on the stone.

Garnet refers to a group of closely related silicate minerals that occur in a wide spectrum of natural colors. While deep red is the most familiar, garnets can also be green, orange, purple, pink, brown, and even black. Major gem varieties include almandine, pyrope, spessartine, grossular, and andradite. Garnet has been used since ancient times and is valued for its durability, brilliance, and diversity.

Garnets are typically transparent to translucent, with no cleavage, and are suitable for most jewelry types. Major sources include Africa (notably Tanzania, Namibia, Madagascar), India, Sri Lanka, Brazil, the United States, and Russia.

Lapis lazuli is a deep-blue metamorphic rock prized as a semi-precious stone. It’s primarily composed of the mineral lazurite (Na3Ca(Al3Si3O12)S), with calcite, pyrite, and minor minerals as common inclusions. It has been used as a gemstone, pigment, and ornamental material for thousands of years.

Lapis is typically an intense royal blue, often flecked with gold-colored pyrite and sometimes white streaks of calcite. It is usually opaque and is cut as cabochons, beads, and inlays.

Moonstone is a gem-quality variety of the mineral feldspar, primarily orthoclase (KAlSi3O8) and sometimes albite. Its signature optical effect—called adularescence—is a soft, billowy light that floats across the stone’s surface, caused by light scattering between microscopic layers of feldspar.

Moonstone is typically translucent to semi-transparent. It is most often cut en cabochon to best display its glow. The finest moonstones have a colorless body with strong blue sheen, but stones also appear in gray, peach, brown, yellow, and even rainbow varieties.

Morganiteis the pink to peach-colored variety of beryl (Be3Al2Si6O18), the same mineral family as emerald and aquamarine. Its color comes from trace amounts of manganese. Morganite is prized for its clarity, durability, and attractive pastel hues, making it especially popular in engagement rings and fashion jewelry.

Onyxis a banded variety of chalcedony, a cryptocrystalline form of silica (SiO2). While pure black onyx is highly sought after for jewelry, natural onyx typically features parallel layers of black and white, with solid black stones commonly produced by dyeing agate. Onyx is opaque with a waxy luster and is valued for beads, cameos, and inlay work.

Opalis a hydrated amorphous form of silica (SiO2·nH2O), prized for its unique play-of-color—an optical effect resulting from the diffraction of light by microscopic silica spheres. Opal can be transparent, translucent, or opaque, and comes in a broad range of body colors, including white, black, gray, orange (“fire opal”), and blue-green. Black opal, mainly from Australia, is the rarest and most valuable. The gem is relatively soft and sensitive to sudden temperature change, impact, and chemicals.

Pearlis an organic gemstone formed inside the soft tissue of living shelled mollusks, mainly oysters and mussels. Natural pearls occur when an irritant becomes trapped inside the mollusk, which then coats it with layers of aragonite and conchiolin, creating a lustrous sphere or shape. Most pearls on the market today are cultured. Pearls can be spherical, oval, or baroque (irregular). They are valued for their luster, surface quality, size, shape, and orient (iridescence).

Peridot is the gem-quality variety of the mineral olivine, with a distinct olive-green color caused by iron content in its crystal structure. Unlike many gemstones, peridot naturally occurs in only one color spectrum—ranging from yellow-green to olive to brownish-green, depending on iron concentration. Notably, peridot can be found in volcanic rocks (basalt), mantle xenoliths, and, very rarely, in some pallasite meteorites.

Rhodolite is a rose-red to purplish-red variety of garnet, belonging to the pyrope–almandine series. Its name is derived from the Greek wordrhodon, meaning “rose-like,” reflecting its vibrant color. Unlike many garnets, rhodolite typically exhibits excellent transparency and few inclusions, making it highly desirable for faceted jewelry. Its color range is due to a specific mix of magnesium and iron in its chemical structure.

Ruby is the red variety of the mineral corundum (Al2O3), colored by trace amounts of chromium. Only corundum with sufficient red saturation qualifies as ruby; lighter shades are classified as pink sapphire. Rubies are highly prized for their intense color, durability, and rarity. The finest rubies are known for their vivid “pigeon’s blood” red, a term describing a pure, vibrant red with a hint of blue.

Sapphire is the gem-quality variety of corundum (Al2O3), second only to diamond in hardness. While blue is the most well-known hue, sapphires actually occur in every color except red (which is classified as ruby). Non-blue sapphires are called “fancy sapphires.” Sapphires are valued for their durability, brilliance, and broad color range.

Spinel is a gem-quality oxide mineral with the formula MgAl2O4. Often confused with ruby and sapphire in history, spinel occurs in a wide range of vivid colors. It is valued for its excellent hardness, high clarity, and strong, saturated hues. Major sources include Myanmar (Burma), Sri Lanka, Vietnam, and Tanzania.

Tanzanite is a blue to violet variety of the mineral zoisite (Ca2Al3(SiO4)(Si2O7)O(OH)), found exclusively in the Merelani Hills of northern Tanzania. It is prized for its intense trichroic color, which ranges from blue to violet to burgundy depending on viewing angle and lighting. Most tanzanite on the market is heat treated to produce its signature blue-violet hue.

Topaz is an aluminum fluoro-silicate mineral (Al2SiO4(F,OH)2) prized for its excellent clarity and range of colors. While naturally occurring topaz is most commonly colorless, yellow, or brown, it can also be found in shades of blue, pink, orange, green, and even red—though many colors result from treatments such as irradiation and heat. The most valuable “Imperial Topaz” is a rich golden orange to pinkish-orange hue.

Tourmaline is a group of boron silicate minerals with a complex and variable chemical formula, most commonly represented as (Na,Ca)(Mg,Li,Al,Fe,Mn)3Al6(BO3)3Si6O18(OH)4. It is prized in the jewelry trade for its extensive color range—including green, pink, red, blue, brown, black, colorless, and even multi-colored crystals (such as "Watermelon Tourmaline," which displays a green rim and pink core). Tourmaline crystals are usually elongated and vertically striated, with strong pleochroism (color changes when viewed from different angles).

Turquoise is an opaque, copper-aluminum phosphate mineral (CuAl6(PO4)4(OH)8·4H2O), valued for its distinctive blue to blue-green color, which is caused by trace amounts of copper (blue) and iron (greenish tones). It often forms in arid climates and is commonly found in nodular, vein, or massive forms, sometimes with a black, brown, or gray matrix.

Zircon is a natural zirconium silicate (ZrSiO4) and one of the oldest known minerals on Earth. Highly refractive and often heat-treated to enhance color, zircon is best known for its vivid sky blue variety, but it also occurs in colorless, golden, red, brown, green, and orange hues. Its strong dispersion (“fire”) gives cut stones brilliance similar to diamonds, making zircon a popular and affordable choice for jewelry.