Semi-Precious Gemstones

Semi-precious gemstones give you beauty and value at a reasonable cost.

There are three traits shared by gemstones:

• beauty – color, symmetry of cut, surface appearance and transparency (translucent or opaque)

• durability – hardness (resistance to scratching), toughness                (resistance to breakage & chipping), and stability (sensitivity to                  light, heat, or chemicals).

• rarity

Of four criteria used to evaluate gemstones (cut, color, clarity & carat weight), color is the most important for colored gemstones.  Gemstones can be organic like amber, coral, jet, pearls and shell or inorganic from crystalized minerals. Most of the minerals listed are crystalized oxides and silicates. These are some gemstones that are used in Sherilyn Designs' jewelry.

 

Abalone – Mother-of-Pearl from a mollusk shell, also referred to as paua shell in New Zealand; mainly sourced from Australia, New Zealand, and United States.

Agate – a form of chalcedony quartz, most occurring in volcanic lava, band layers in various colors; moss agate is translucent with moss-like pattern in brown and red with green irregularities. Found in Brazil, China, Egypt, Germany, India, Italy, Mexico, Scotland, United States, and Uruguay.

Amazonite – semi-opaque green sodium variety of feldspar and can be confused with turquoise or jade. Found in Brazil, Canada, India, Madagascar, Namibia, Russia, Tanzania, and United States.

Amber – organic, fossilized pine tree sap, can be white, orange, yellow, brown, green, blue, red, or violet. Most important sources are Dominican Republic, Germany, Poland, and Russia as well as being found in Canada, Czech Republic, France, Italy, Japan, Mexico, Myanmar, Romania, Spain, and United States.

Amethyst – a variety of quartz ranging from light to deep purple with reddish overtones. Found in Australia, Bolivia, Brazil, Canada, Germany, India, Madagascar, Mexico, Namibia, Russia, Sri Lanka, United States, Uruguay, and Zambia.

​

Apatite – form Greek for “I am misleading” as it has the appearance of other gemstones, turquoise blue, also in yellow, green, brown, white and violet. Found in Africa, Brazil, Canada, Germany, Madagascar, Mexico, Myanmar, Russia, Spain, Sri Lanka, Sweden, Switzerland, and United States.

​

Aquamarine – from Latin for "sea water," a blue or blue-green gemstone in the beryl family. Found in Afghanistan, Australia, Brazil, China, India, Kenya, Madagascar, Mozambique, Nigeria, Pakistan, Russia, United States, and Zambia.

Aventurine – also called aventurine quartz, from Italian "by chance," has colorful play of glittering reflections called “aventurescence” green quartzite material. Found in Brazil, India, Japan, Russia, Tanzania, and United States.

Carnelian – chalcedony quartz family, usually red or reddish orange. Found in Brazil, India, United States, and Uruguay.

Cat’s Eye – quartz family, “Chatoyancy” cat’s eye effect is needle-like straight line irregularities in the middle of the stone like when light catches a cat’s eyes in the dark. Found in Brazil, India, and Sri Lanka.

Citrine – from French meaning "lemon," yellow variety of quartz, but can be deeper orange-yellow or reddish. Found in Bolivia, Brazil, Madagascar, and Russia.

Coral – organic skeleton of coral polyps in red, pink, white, black, golden, and blue. Harvested by divers reduces damage to corals. Found in Mediterranean Sea - Algeria, Italy, Morocco, Sardinia, Tunisia; Pacific Ocean – Hawaii, Japan, Malaysia, Philippines, Taiwan; Persian Gulf, and Red Sea.

Crystal – Greek for “ice,” quartz. Found in various locations around the world and in Brazil, Madagascar, United States and the Alps.

​

Eye of Shiva – white shell with a naturally occurring concentric pattern, resembling an ethereal eye, composed of concentric rings of different colored brown and black agates and wash up on riverbanks in India.

Fluorite – Latin “to flow,” translucent and transparent of various colors, streaked white. Found in Argentina, Austria, England, France, Germany, Myanmar, Namibia, Switzerland, and United States.

Garnet – Colored minerals, usually pyrope and almandite varieties, in almost all colors except blue and found in various locations around the world.

Hematite – from Greek “blood,” black, black-gray to brown-red with a high luster; high density makes it heavy. Found in Canada, England, Norway, Sweden, and United States.

Howlite – Milky white with black or dark brown veins, white streaks.

Jade – from translucent to opaque and is the toughest colored gemstone. Jadeite Jade found in green, black, brown, blue, lavender, orange, pink, red, and white. Found in Guatemala, Japan, Myanmar, Russia, Tibet, and United States. Nephrite Jade is darker and has a greasy appearance, in light to dark green, black, brown, gray, yellow, and white. Found in Australia, Canada, China, Mexico, New Zealand, Russia, Taiwan, and United States.

Jasper – chalcedony, but sometimes considered quartz family, from Greek meaning “spotted stone”; usually multicolored, striped or flamed. Found in Australia, Brazil, Canada, Egypt, India, Kazakhstan, Madagascar, Russia, United States, and Uruguay.

Jet – bituminous coal, has a waxy, velvety luster. Found in England, France, Germany, Poland, Spain, and United States.

Labradorite – a plagioclase feldspar, has “schiller” iridescence in metallic tints often in blue and green. Found in (Labrador) Canada, Finland, India, Norway, and Russia.

Lapis Lazuli – opaque, in Arabic and Latin means ‘blue stone,’ is considered a rock not a mineral, can have white veining or metallic diamond-like specks. Found in Afghanistan, Angola, Argentina, Myanmar, Canada, Chile, Pakistan, Russia, and United States.

Malachite – an opaque green, can contain dramatic banding or floral patterns. Found in Australia, Russia, United States, and Zaire.

Moonstone – a potassium feldspar, has a white or blue shimmer moving across the stone when rotated in the light called "adularescence.” Found in India, Myanmar, and Sri Lanka.

Mother-Of-Pearl – iridescent, made of nacre (like pearls) lining a mollusk shell. Found natural in Gulf of Manaar (Indian Ocean), Persian Gulf, and Red Sea; cultured in Australia, China, Japan, and Polynesia; freshwater in China, Japan, and United States.

Obsidian – black, gray, brown, green, can have golden or silver sheen. Found in Ecuador, Iceland, Indonesia, Italy, Japan, Mexico, and United States.

Onyx – layer stone, of chalcedony or agate of black and white, or uni-colored chalcedony “black onyx,” the best source is Brazil.

Pearl - Freshwater – irregularly shaped river pearls made by oyster-type mollusks coating an irritant inside its shell with nacre (mother-of-pearl). Found in United States.

Peridot – transparent green. Found in Australia, Brazil, China, Egypt, Myanmar, Norway, Pakistan, South Africa, and United States.

Quartz – from Slavic word meaning “hard," some with a star-effect called “asterism” needle-like irregularities in intersecting patterns; pink crackled variety is Rose Quartz. Found in Brazil, India, and other locations.

Rhodonite – opaque pink, sometimes with black spots or veining, from the Greek word for “rose.” Found in Australia, India, Mexico, Russia, Sweden, and United States.

​

Ryolite - also known as 'Que Sera' is a mixture of different stones including quartz and feldspar, almost half jasper and half agate, green. Found in Brazil.

Sardonyx – layer stone of chalcedony or agate with parallel layers of white, sourced in Brazil.

Sodalite – blue with white veins. Found in Brazil, Canada, Greenland, India, Namibia, Russia, and United States.

Tiger’s Eye – quartz family, usually opaque, “chatoyancy” cat’s eye effect is needle-like straight line irregularities in the middle of the stone like cat’s eye usually as stripes, but in warm tones of brown and yellow. Found in Australia, India, South Africa, Sri Lanka, and United States.

Tourmaline – in a variety of yellow, green, blue, violet, pink, red, and brown; stones with red core, white inner layer and green outer layer called “watermelon.” Found in Afghanistan, Brazil, Kenya, Madagascar, Mozambique, Myanmar, Namibia, Pakistan, Russia, South Africa, Sri Lanka, and United States.

Turquoise – from French for “Turkish stone,” opaque blue with brown, dark gray or black veining or spider web matrix on the surface, some with greenish color. Found in Afghanistan, Argentina, Australia, Brazil, Israel, Mexico, Tanzania, Iran, and United States.

Source material:
“Gemstones of the World, Newly Revised Fifth Edition” by Walter Schumann
“Colored Gemstones” by Paul Deasy

​