Color Change Garnet Gemstone Information
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About Color Change Garnet - History and Introduction
Color change garnet is an especially rare and valuable member of the garnet group of gemstones. It is highly desired for its distinct ability to change color depending on the type of light source with which it is viewed. The ability to color change is often erroneously mistaken for pleochroism, which is the ability to exhibit different colors depending on the viewing angle, whereas the phenomena of color change is not dependent on the viewing angle. Color change garnet is typically a hybrid-mix of spessartite and pyrope garnet and in many cases, may also contain traces of grossularite or almandine garnet.
With color change garnet, the intensity of color-change can be quite dramatic, often surpassing that of the finest alexandrite. Most color change garnet will exhibit a brownish-green or bronze color when viewed under natural daylight, but when viewed under incandescent light, it will appear rose to pink in color. There are a variety of other color change combinations possible. In order to truly appreciate the full range of color change garnet, specimens should be observed under a variety of lighting conditions, including early morning daylight, late afternoon daylight, fluorescent light and incandescent light or candlelight.
Theoretically, the garnet group is comprised of two mineral series - the aluminum silicates, consisting of pyrope, almandite and spessartite; and the calcium silicates, consisting of uvarovite, grossularite and andradite. The main differences among these members are slight variations in color, density and refractive index. Despite being distinct species with very distinct compositions, all garnet varieties share the same crystal structure; rhombic dodecahedron, twelve-sided crystals with rhombic faces. This crystal form is the hallmark of all garnet gemstones and minerals.
Other than the ability to change hue, color change garnet is identical to malaya (malaia) garnet by composition. Color change garnet can be easily identified from other garnet when viewed under different light sources. Color change garnet can sometimes be mistaken for alexandrite, but can easily be distinguished by its distinct level of hardness. Alexandrite is also rarely found in larger sizes, often weighing less than just a half carat, whereas color change garnet is commonly found in sizes well over one carat.
Color Change Garnet Origin and Gemstone Sources Back to Top
As a group, garnet gemstones are a relatively common occurrence that form in highly metamorphosed rocks and igneous formations under extremely high pressure and temperatures. Today, the leading supplier of color change garnet is East Africa, particularly the Umba Valley in Tanzania. Other notable sources include Sri Lanka (Ceylon), Madagascar, Norway, Tunduru and the USA.
Color change garnet from East Africa is typically a mix of spessartite, grossularite and varying ratios of almandine or pyrope. The color-change is typically greenish-yellow to brown under transmitted fluorescent light and purplish-red under reflected fluorescent light; under incandescent light the color shifts from reddish-orange to red. Spessartite-grossular-pyrope specimens typically appear light bluish-green under transmitted fluorescent light and violet-purple under reflected fluorescent light; under incandescent light, the color shifts from light-red to purplish-red.
Sri Lanka (Ceylon) is known to produce a fine material which shifts from blue, green or grayish (daylight) to reddish-purple (incandescent light).
Some of the finest color change garnet is mined from Bekily in Southern Madagascar. This fine material is known to exhibit a very strong color change from greenish-brown to red-pink. Some may exhibit various shades of orange.
The USA's color change garnet from Idaho is mostly a mix of almandine and pyrope garnet by composition. This is famed for its red to purplish-red change.
Norway is known to produce a color change garnet which shifts strongly from violet (daylight) to claret (incandescent light) and violet-red to blue-green. The crystals from Norway are typically quite small, often weighing less than 1 carat, but they're prized because of their alexandrite-like intensity of color change.
Buying Color Change Garnet and Determining Color Change Garnet Gemstone Value Back to Top
Color Change Garnet Color
Color change garnet changes hue based upon the source of light. The most common shift is from red to green. In daylight, color change garnet can appear green to gray and in some cases, blue. When viewed under direct incandescent light, colors can appear violet to purple similar to amethyst. Under candlelight, color change garnet can exhibit a deep almost blood-like color. Other color combinations that are possible are reddish-orange to red, greenish-yellow to pinkish-red, light-red to purplish-red and bluish-green to light violet-purple.
Color change ability is an extremely rare occurrence that is known to occur in only a handful of gems. The color change ability is present in rare specimens that have formed with two light transmission windows (rather than one) that are approximately the same size. For example, a red gemstone will appear red because it absorbs all frequencies of light except for red; but a gemstone that absorbs all frequencies of light except for blue and red, will appear blue when the light source is rich in blue wavelengths, and will appear red when the light source is rich in red wavelengths. Fluorescent light is rich in blue, whereas incandescent light and candlelight are rich in red wavelengths. Natural daylight has a very well-balanced spectrum throughout most of the visible light wavelengths.
Color Change Garnet Clarity and Luster
Color change garnet is typically transparent, but inclusions are quite common like some other garnet varieties. Eye-clean specimens in large sizes are especially rare. The finest specimens exhibit a vitreous, glass-like luster once cut and polished.
Color Change Garnet Cut and Shape
Color change garnet is typically faceted to maximize its color shift ability. Ovals and round shapes are most common, but cushions and emerald step-cuts are also quite popular. Fancy shapes, including pears, hearts and trillions are quite rare, though not unheard of.
Color Change Garnet Treatment
Like most garnet gemstones, color change garnet is not known to be treated or enhanced in any way.
Color Change Garnet Gemological Properties: Back to Top
||[Mg3 + Mn3]AL2(SIO4) - Manganese aluminum silicate
||Cubic - rhombic, tetrahedron
||Light-bluish, green, purple under white light; light-red to purplish and pink under incandescent light.
||7 to 7.5 on the Mohs scale
||1.73 - 1.81
||3.65 to 4.20
||Transparent, translucent, opaque
|Double Refraction or Birefringence:
Please refer to our Gemstone Glossary for details of gemology-related terms.
Color Change Garnet: Varieties or Similar Gemstones:
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The garnet group of gemstones is one of the most important in the gem trade. Garnet is most well-known for its classic red gemstone form, but they can also occur in various other colors, including green, blue, brown, pink and purple. Owing to garnet deposits forming in scattered locations around the world, there are a number of other gemstones which can be easily mistaken for garnet. Some of the most commonly confused gems include chrysoberyl, alexandrite, tourmaline and sapphire.
Although there are only six mineral species of garnet, there are several more distinct gemstone forms. This is because garnet very commonly forms with more than one mineral species. In fact, garnet is very rarely in pure form.
Most Popular Related Gem and Mineral Associations:
Star garnet, pyrope garnet, almandine garnet, rhodolite garnet, spessartite, grossularite, tsavorite garnet, demantoid garnet and malaya (malaia) garnet are among the most popular garnet varieties.
Lesser-Known Related Gem and Mineral Associations:
Hydrogrossular garnet, andradite garnet, melanite, tapazolite, uvarovite, Mali garnet, hessonite garnet, leuco garnet and umbalite are among the lesser known garnet varieties.
Color Change Garnet Gemstone Mythology, Metaphysical and Healing Powers Back to Top
The name 'garnet' comes from the Latin word 'garanatus', which means 'seed-like', in reference to pomegranate fruit seeds. Although the distinction of the color change garnet variety is relatively new, garnet stones in general have been widely known for thousands of years. The Greeks believed that garnet protected their children from drowning and it was thought to be a potent anecdote against poison. The Koran notes garnet as a stone which illuminates the fourth heaven. Hebrew and Christian scriptures refer to garnet as one of the twelve stones embedded in Aaron's breastplate, and it was also reported that Noah used a garnet lantern to safely steer his ark through the darkness of night.
Garnet is a traveler's stone. Many courageous discoverers and adventurers were well-known for wearing garnet for protection. It was considered to be a powerful talisman, capable of illuminating the night and dispelling evil spirits. Garnet was often used to lift depression and to rid people of bad dreams. Physically, color change garnet is thought to alleviate arthritis, varicose veins, backache, liver disorders and help prevent hemorrhages.
Garnet is the stone for Aquarius and the official modern birthstone for January. In addition, it is also the 2nd marriage anniversary stone. Additionally, garnet is considered to be the planetary stone for Mars, Mercury and Pluto.
Disclaimer: Metaphysical and Alternative Crystal Healing Powers and Properties are not to be taken as confirmed advice. Traditional, Ceremonial and Mythological Gemstone Lore is collected from various resources and is not the sole opinion of SETT Co., Ltd. This information is not to replace the advice of your doctor. Should you have any medical conditions, please see a licensed medical practitioner. GemSelect does not guarantee any claims or statements of healing or astrological birthstone powers and cannot be held liable under any circumstances.
Color Change Garnet Gemstone and Jewelry Design Ideas Back to Top
Color change garnet is ideal for any type of jewelry application. Like all garnet gemstones, it has excellent hardness, brilliance and durability. Perhaps best of all, it is quite affordable compared to other popular jewelry gemstones. Color change garnet is perfectly suitable for everyday rings, necklaces, bracelets, brooches, pins and pendants. The rarity of color change garnet tends to attract high-end jewelry designs, rather than mainstream jewelry applications.
Since garnet is one of the official modern birthstones, it remains one of the most popular colored gemstones on the market.
Note: Buy colored gemstones by size and not by carat weight. Colored stones vary in size-to-weight ratio. Some stones are larger and others are smaller than diamond by weight in comparison.
Color Change Garnet Gemstone and Jewelry Care and Cleaning Back to Top
Color change garnet can be cleaned with warm water and a mild soap or detergent. You can wipe down your stones with a plain soft cloth or brush. After wiping, be sure to rinse your gems and jewelry well to ensure all soapy residue is removed. Avoid extreme heat, as extreme temperature fluctuations can cause fracturing. Ultrasonic cleaners are considered safe, but are still not recommended. Steamers should be avoided, as well as any harsh household chemicals and cleaners, including bleach or hydrofluoric acid, as chemicals can cause corrosion.
Although color change garnet is quite durable, it is still recommended that jewelry be removed before engaging in vigorous physical activities, such as exercise or sports. When removing jewelry, do not pull from the stone as this can weaken prongs, eventually leading to a lost stone. When storing color change garnet gemstones, wrap them in a soft cloth or place them inside a fabric-lined jewelry box.