Gemstone in World

Almandite

Almandite/Garnet

Almandite is probably one of the most familiar of the closely related species that make up the garnet group. It’s a fairly common red garnet, with a color range from orangy red through red to reddish purple. Almandite was named for Alabanda, an ancient Asian town and an active gemstone trading and fashioning center. Ancient Romans often fashioned almandite garnets as thin, hollowed cabochons to bring out the intensity of their color. Other species in the garnet group come in a variety of hues, from browns and oranges to vibrant greens. As far back as 3100 BC, Egyptians along the Nile worked garnet into beads and inlays. Noah is said to have recognized garnet’s inner fire and used it as a lamp on the bow of the ark. Garnets of all species, including almandite, are considered January birthstones.

Amber

Amber belongs to the category of organic gems—the products of living organisms and biological processes. Amber formed millions of years ago, when sap from ancient trees hardened and fossilized. Stone Age people discovered these golden jewels along the shores of the Baltic Sea, and they became perhaps the earliest and most consistently popular ornamental gems. Scientists and collectors treasure amber that contains suspended animal or plant fragments: Fossilized bits of once-living things that were trapped in the hardening amber millions of years ago, creating a fascinating time capsule. Some types of amber are found in the ground. Other types have been freed and carried by tides and end up on beaches or near-shore areas. The Baltic coast bordering Germany, Poland, and Russia is still a source of amber, which is sometimes called “gold of the North.” Amber’s warm luster is featured in beads, carvings, pendants, and cabochon rings, as well as decorative items like cups, bowls, snuff boxes, and umbrella handles. Amber’s colors range from whites, yellows, and oranges to reds and browns. Clear material is preferred in the US, cloudy in Europe and North Africa. Heating cloudy amber in oil clarifies it. Heat treatment can also produce disk-like stress fractures and create an attractive product called sun-spangled amber.

Treatments:

 Treatment              Heating

Purpose                  removes yellow,resulting in purer blue color

Stability                   very good

Prevalence              Routine

Detection                Undetectable

 Care and Cleaning:

Type of Cleaning                             Advisability

Ultrasonic cleaning     

               Usually safe, unless stone contains feathers or liquid inclusions

Steam cleaning  

              Usually safe, unless stone contains feathers or liquid inclusions

Warm, soapy water                         Safe

Cat’s-Eye

Cat’s-Eye/Chrysoberyl

This gem, with its band of reflected light across the middle, has always reminded observers of the eye of a cat. The cat’s-eye effect, also called chatoyancy, is caused by parallel needle-like inclusions within the stone. The gem was once known as cymophane-Greek for “waving light.” In some cultures, its distinctive appearance made it the preferred treatment for all sorts of eye ailments. Chatoyancy appears in other gemstones, but fine-quality cat’s-eye chrysoberyl sets the standard. It’s also the most valuable cat’s-eye stone. It’s durable as well as attractive, which makes it popular in men’s rings, cufflinks, and tie tacks. The cabochon cut brings out its cat’s-eye effect to best advantage. Cat’s-eye chrysoberyl ranges from brown to greenish yellow. The finest quality specimens boast a golden color, with bands that span the entire length of the gem. The bands themselves are distinct, silvery-white, and straight. The chatoyant band in cat’s-eyes will appear to blink when you hold the stone between two light sources, then rotate it. As you turn the stone, the eye splits into two bands that move apart, then back together. This effect is called “opening and closing.” Cat’s-eyes display another impressive effect, called milk and honey. With the light positioned perpendicular to the chatoyant band, the side nearest the light shows the stone’s original bodycolor while the other side has a milky appearance.

Citrine

Citrine/Quartz

Citrine is one of the US birthstones for November (the other is topaz). It’s a quartz variety, and the top-selling transparent gem in the yellow to orange color range. Its name was derived from the Latin word citrus, meaning “citron” (a fruit closely related to the lemon). This gem combines a warm, attractive color with good wearability and a moderate price—an unbeatable combination for many customers. Citrine comes in an exceptionally wide range of sizes. The largest transparent faceted gem on record (in terms of dimensions and volume) is a citrine. It measures 25.5 cm ˘ 14.1 cm ˘ 10.0 cm (9.9 in. ˘ 5.5 in. ˘ 3.9 in.), and weighs 19,548 cts. (3.9 kg/8.6 lb.). Jewelry-sized citrines are readily available in weights of up to 20 cts. and more. Most citrine is faceted in traditional rounds and fancy shapes, but you’ll also find it fashioned into more unusual cuts and carvings. Leading jewelry designers use citrine alone, in combination with diamonds, and in multicolored creations alongside gems with contrasting colors— amethyst, aquamarine, blue topaz, and others. Before the development of modern gemology, citrine was traditionally confused with topaz because of their similar colors.