Semi-Precious Gemstones A -F

In this glossary you will find a world of information on most of the materials we use in our handcrafted beaded jewelry designs at Bonnico Jewelry Designs. Featuring semiprecious gemstones from A to Z, different types of glass and lampwork beads, shells, differences in the types of the silver and gold we use and even birthstone colors and common jewelry sizes to help you decide if the size is right for you.

Agate

Colors will vary. These stones can be found in major deposits in Brazil and Uruguay, also found in Australia, the Caucasus, China, India, Madagascar, Mexico, Mongolia, Namibia and the United States.

This stone’s signature is dramatically banded varieties of chalcedony and is composed of quartz layers. This composition varies greatly and can be of many colors such as white, yellow, orange, blue, brown and black. The other chalcedony family, jasper, has less-regular patterns and is less defined than the agates.

Amazonite

Colors are blue-green, pale green. These stones can be found in Brazil, India, Kenya, Madagascar, Namibia, Russia, United Sates (Colorado) and Zimbabwe.

Amazonite is a rare blue-green variety of microcline from the feldspar family (which includes moonstone, labradorite, and aventurine). The stone is mostly opaque and derives its name from deposits originally found in the Amazon. Amazonite is an opaque stone, often found with white, yellow or gray inclusions and a silky luster or silvery sheen.

Amber

Colors are yellow, brown (green when heated). These stones can be found in major deposits in Russia, also found in Canada, China, the Dominican Republic, Italy, Japan, Mexico, Myanmar (Burma), Romania, and the United States (Alaska and New Jersey).

Amber is fossilized pine resin of now extinct conifer trees and ancient pines. Trees release the resin as a protective mechanism against disease and insect infestation. Then it was hardened and became preserved in the earth's crust for millions of years. Amber is an amorphous stone, meaning that like glass, it does not have an ordered structure. Ambroid, often mistaken for genuine amber, is a material made by compressing and heating pieces of amber together.

Amethyst

Colors are purple to reddish-violet. These stones can be found in most important deposits in Brazil, Madagascar, Uruguay and Zambia. Also found in Canada, India, Mexico, Myanmar (Burma), Namibia, Russia Sri Lanka, and the Untied States (Arizona).

Amethyst is formed in silica-rich liquids deposited in gas cavities (geodes) in lava. It occurs in crystalline masses, but the crystals are generally not well developed, so they generally are found as clusters of crystal points. Though geodes are the best place to locate amethysts, they also sometimes grow as stalactites. Amethyst is usually consistently pure in color. Amethyst quartz, which beads are often made of, is striped with milky quartz.

Aventurine

Colors are dark green: also comes in reddish-brown and golden brown. These stones can be found in Austria, Brazil, India, Russia and Tanzania.

Aventurine is a form of chalcedony that contains small inclusions of various shiny minerals. These materials, usually spangles of mica or iron oxide, give the stone a glistening effect. Aventurine's granular appearance and particular translucence are its most distinctive characteristics. When you buy aventurine, do not confuse it with jade or glass. It is also called aventurine quartz.

Carnelian

Colors are reddish-brown to orange. These stones can be found in Brazil, India, and Uruguay.

Carnelian is related to chalcedony. It is heat-treated in secret, well before reaching the gemstone-cutting factory. This actually has been a secret for thousands of years. Each part of the world thought everyone else's carnelian was naturally red, but they were heating theirs, as well. When held against the light, the color-treated carnelian shows its color in stripes, while natural carnelian shows a cloudy distribution of color. Carnelian is related to chalcedony. When you buy carnelian, be sure you are not buying red agate, which has stripes rather than clouds of color.

Chalcedony

Colors are blue, purple, pink, white, yellow, orange, and gray. Blue and purple are the most popular hues. These stones can be found in Brazil, India, Madagascar, Namibia, Sri Lanka, the United States (California), Uruguay and Zimbabwe.

The name usually refers to semitransparent or translucent with a solid color, commonly pale bluish-gray, and nearly wax like luster. Blue agate beads are often confused with chalcedony beads.

Some are unsure how to pronounce "chalcedony" — the most common way to pronounce chalcedony is kal-SEH-doh-nee; also accepted are chal-SEH-doh-nee, KAL-seh-DOH-nee and CHAL-seh-DOH-nee.

Citrine

Colors are light to dark yellow. These stones can be found in Argentina, Brazil, Madagascar, Myanmar (Burma), Namibia, Russia, Scotland, Spain, and the United States.

Citrine is named for its lemony color. Almost all beads on the market that are called citrine are actually heat-treated amethyst or smoky quartz. It just takes a kiln that can reach a specific temperature and hold it for long enough, and a purple amethyst will turn to citrine. Natural citrine is not common and occurs in lighter hues than the heat-treated material. Also, heat-treated forms often can be distinguished from natural citrine by their red tint (a quality of all heat-treated gemstones).

Cross stone

(Chiastolite Andalusite) Colors are generally black, brown and/or olive green in gem grade. These stones were discovered in Spain and can be also be found in Australia, Austria, Chile, China, England, Finland, France, Germany, Ireland, Italy, Japan, Portugal, Scotland, South Africa, Brazil and the United States.

The crystals of Andalusite contain cross-shaped inclusions of carbon and called the Chiastolite, or a Cross Stone or Macle. It is found in metamorphic and contact metamorphic zones and composed of Aluminum Silicate. This forms in carbonaceous clayey slates. The crosses (Chiastolite) in the stone will form when carbon rich impurities develop an axis along the crystal. Cross stone is also considered a gemstone to enhance the intellect, problem solving abilities and mental clarity. Some natural healers will use it to bring protection and balance during periods of upset or change.

Fluorite

Colors are extremely variable. They can be an intense purple, blue, green or yellow; also colorless, reddish orange, pink, white and brown. A single crystal can be multi-colored. These stones can be found in Brazil, Canada, China, England, Germany, Morocco, Spain and the United States (Tennessee, Indiana, Ohio and Colorado).

Fluorite is well known and prized for its glassy luster and rich variety of colors. The range of common colors for fluorite starting from the hallmark color purple, then blue, green, yellow, colorless, brown, pink, black and reddish orange is amazing and is only rivaled in color range by quartz.