Best Gemstone

Cat's eye apatite is a variety of apatite that shows chatoyancy, a narrow reflective band that moves across the surface of a polished cabochon. The effect is produced by aligned inclusions within the phosphate mineral and is most visible when the stone is cut en cabochon rather than faceted. Materia...

Axinite is a group of calcium-bearing borosilicate minerals known for strongly pleochroic colors, in which the apparent color changes with viewing direction. Its crystals commonly have flattened, wedge-like forms, and specimens may range from brown and violet to yellow or gray. Axinite occurs mainly...

Anyolite is a green metamorphic rock commonly known as ruby in zoisite. It consists mainly of green zoisite with contrasting red ruby crystals and darker inclusions of hornblende, producing a distinctive mottled appearance. The material is associated with deposits in northeastern Tanzania, where it...

Moss agate is a variety of chalcedony, a microcrystalline form of quartz, containing green, brown, or black inclusions that can resemble moss, branches, or other plant forms. The inclusions are usually mineral material rather than fossilized vegetation and create patterns that vary from stone to sto...

Carnelian is a translucent variety of chalcedony, a microcrystalline form of quartz, with colors ranging from orange and reddish orange to brownish red. Its color is commonly linked to iron impurities, and the stone can be polished or carved into beads, seals, and other objects. Carnelian was used w...

Celestite is a mineral composed of strontium sulfate and is named for its pale sky-blue color, although it can also occur in white or other shades. It forms crystals and geodes that are collected as mineral specimens and, when transparent and attractive, may be cut or displayed as a gemstone. Import...

Ferro-axinite is an iron-rich calcium borosilicate mineral in the axinite group. It is commonly recognized by its clove-brown to brown color, strong pleochroism, and sharp wedge-shaped crystals. The mineral forms mainly in contact metamorphic settings, where heated igneous bodies alter surrounding c...

Bloodstone, also called heliotrope, is a dark green variety of chalcedony marked by red spots or patches caused by iron oxide minerals. The contrast between the green base and red inclusions is its defining visual feature. It has been collected and used for carved objects and jewelry for centuries,...

Scorodite is a hydrated iron(III) arsenate mineral with the chemical composition FeAsO4·2H2O. It commonly forms as a secondary mineral when arsenopyrite and other arsenic-bearing minerals undergo oxidation in ore deposits. Crystals may be blue, blue-green, green, or gray and can be transparent to tr...

Kyanite is an aluminosilicate mineral with the chemical formula Al2SiO5. It is distinguished by strong directional variation in hardness: its hardness differs depending on whether a specimen is tested parallel or perpendicular to its crystal structure. Kyanite commonly occurs in blue, although other...

Magnesite is a mineral composed primarily of magnesium carbonate, with the chemical formula MgCO3. It commonly occurs in white, grey, or pale brown masses and has a dull to glassy appearance, although some material is cut and polished for ornamental objects and jewellery. Magnesite is also frequentl...

Ivory is a hard, dense form of dentine found in the tusks of elephants and in the teeth or tusks of some other mammals. It has been used for centuries in carving, decorative objects, musical instruments, and inlay because it can be cut, polished, and given a smooth surface. The international commerc...

Actinolite is a calcium magnesium iron amphibole mineral that forms a compositional series with tremolite. It commonly occurs in metamorphic rocks, especially rocks formed when magnesium- and calcium-rich materials are altered during metamorphism. Actinolite may appear green, gray-green, or nearly b...

Thulite is a pink to reddish variety of zoisite colored mainly by manganese. Zoisite is a calcium aluminum hydroxy-silicate mineral, and thulite is valued as an ornamental and lapidary material because of its opaque color and ability to take a polish. It is strongly associated with Norway, where imp...

Tiger's eye is a variety of quartz that displays chatoyancy, a moving band of reflected light resembling the eye of a cat. Its golden-brown appearance develops from the alteration of fibrous materials related to crocidolite, with quartz preserving a parallel structure that reflects light. The stone...

Rose quartz is a pink variety of quartz used chiefly as an ornamental stone and gemstone. Its color is generally attributed to trace elements and microscopic inclusions, and the material is commonly translucent rather than transparent. Unlike many well-formed quartz varieties, rose quartz typically...

Star diopside is a variety of the pyroxene mineral diopside that shows asterism, a star-like reflection of light. The effect is usually caused by aligned inclusions or internal structures, and properly oriented cabochon cuts can display a four-rayed star. The material is commonly black or very dark...

Pyrope is a magnesium-rich mineral in the garnet group and is usually red to deep red in color. It forms in high-pressure igneous and metamorphic rocks, including some mantle-derived rocks, and its composition can overlap with that of other garnet varieties. Transparent pyrope is cut as a gemstone,...

Galaxite is a rare manganese aluminum spinel with the chemical formula MnAl₂O₄. It occurs in metamorphic rocks and is typically recognized by its opaque black color and metallic-looking luster. Transparent or facetable material is uncommon, so galaxite is primarily of interest to mineral collectors...

Copal is a relatively young tree resin that has not undergone the full geological transformation associated with true amber. Much copal is classified as sub-fossil resin and is less than one million years old, although its age varies by deposit. It is often sold as an amber-like material, but it is...

Hemimorphite is a hydrated zinc silicate mineral with the chemical formula Zn4Si2O7(OH)2·H2O. It forms mainly in the oxidized zones of zinc ore deposits and can occur as white, colorless, blue, green, or brown crystals and crusts. Its name refers to hemimorphic crystals, whose differently shaped end...

Sardonyx is a variety of chalcedony, a microcrystalline form of quartz, with layers of reddish-brown sard and lighter-colored chalcedony. Its parallel bands can be cut to create contrast in engraved designs, making the material suitable for cameos, seals, beads, and other carved ornaments. Sardonyx...

Hawk's eye is a blue to blue-grey variety of chatoyant quartz closely related to tiger's eye. Its silky optical band, known as chatoyancy, results from aligned fibrous inclusions that reflect light across the polished surface. The material develops through alteration of crocidolite-bearing rock and...

Rhodonite is a manganese inosilicate mineral with the chemical formula MnSiO3. It commonly occurs in shades of pink, rose, or red and may contain black veins or patches of manganese oxides, producing a strongly contrasting pattern. The mineral forms in metamorphic rocks and manganese-rich deposits a...

Wood opal is fossilized wood in which the original organic material has been replaced or impregnated by silica while retaining aspects of the wood's structure. The silica may form common opal, and in some specimens it can produce the color changes associated with precious opal. Visible grain, growth...

Afghanite is a rare blue to colorless feldspathoid mineral in the cancrinite-sodalite group. It was first identified in 1968 at the Sar-e-Sang area of Afghanistan, the locality reflected in its name, and it commonly occurs with lazurite and other minerals in lapis lazuli-bearing rocks. Transparent o...

Tremolite is a calcium-magnesium amphibole with the ideal formula Ca2Mg5Si8O22(OH)2. It occurs as colorless, white, gray, green, or pink crystals and as compact or fibrous aggregates; the fibrous form is an asbestos mineral and can be a health hazard when its fibers become airborne. Tremolite is chi...

Smithsonite is a zinc carbonate mineral, ZnCO3, that forms mainly in the oxidized zones of zinc ore deposits. It was historically called calamine in some mining and collecting contexts and received its modern name in 1832 in honor of James Smithson, whose bequest founded the Smithsonian Institution....

Agate is a variety of chalcedony, the microcrystalline form of quartz, usually recognized by bands or other patterns created as silica layers fill a cavity in volcanic or other rock. Its colors and translucency come from fine mineral impurities and changes during deposition, so specimens may show co...

Enstatite is a magnesium-rich orthopyroxene, a pyroxene-group silicate found in many mafic and ultramafic igneous rocks and in some meteorites. Its ideal composition is MgSiO3, although natural specimens commonly contain some iron, which changes their color and places them in the enstatite-ferrosili...