Gemstone Guide

Agate

Said by the ancients to render the wearer invisible, Agate has been admired by humanity for thousands of years. Its beauty and durability have prompted man to use it in both practical and ornamental forms. One of the more outlandish uses is binding an Agate to each horn of your oxen to ensure a good harvest. The danger here is that your appropriately agated beasts of burden may then become invisible and a little hard to find. In 1709 a Brazilian priest planned to use agates as antigravity devices on an air ship he had designed. Agate is believed to cure insomnia, ensure pleasant dreams, protect from danger, promote strength, healing and a bold heart. Wearers become temperate, continent and cautious. Agate is a cooling stone; it reduces fever, quenches thirst, quiets the pulse and heart throbs and ensures good health and a long and prosperous life. Agate is formed in a unique way and many fossils are actually agatized material that has replaced the original organic substance. For example, petrified wood is fossilized wood that has had its organic matter replaced by agate.

The main conditions necessary for agate formation are the presence of silica from devitrified volcanic ash, water from rainfall or ground sources, manganese, iron and other mineral oxides that form the bands and inclusions. Agate is a fine-grained fibrous variety of Chalcedony Quartz and comes in many different forms ranging from transparent to opaque. Varieties include Blue, Blue Lace, Crazy Lace, Green, Indian, Moss, Tree, and Wood. Most popular are: Blue lace agate which has swirly white bands in a blue background; moss agate is so named for its moss-like pattern; fire agate is a brown-bodied stone containing yellow, green, and orange spots, with an iridescent shimmer like opal. As there are so many varieties of agate, it is largely up to the buyer to determine its value. Most agate is in the low price range but some picture stones, carvings and unique pieces may command higher prices. The popularity of fire agate has increased in recent years, as has its price.

Blue Sapphire

The island of Serendib (present day Sri Lanka) holds one of the earliest records for the mining of Sapphires. Ancient people believed that the power of wisdom is contained within this precious gemstone. They believed that when the wearer of a Sapphire faces challenging obstacles, the stone's power enables them to find the correct solution. The modern word Sapphire is derived from the ancient Latin term "Sapphirus". Sapphires come in all spectrums of color, except for red. Often when people refer to Sapphires, they mean "Blue Sapphires". Other color sapphires are referred to as "Fancy Sapphires". Australia and Africa are the world's largest suppliers of "Blue Sapphires". Sri Lanka also provides a large portion of the world's supply of "Blue Sapphires". Gemstones from this island are often called "Ceylon" Sapphires, which was the name of the island before it was changed to Sri Lanka. Pailin, Cambodia, is another source of exceptional "Blue Sapphires". Burma is also known for their top quality supply of this gemstone.

Similar to Rubies, Sapphires come in many different shapes and sizes, providing great variety to gemstone lovers and ensuring the enduring popularity of Sapphire jewelry. With hardness just below that of Diamonds, Sapphires are one of the toughest gemstones, and with no cleavage, breakage rarely occurs. Intense medium dark blue is the most sought after color for Blue Sapphires. However, very fine Sapphires are extremely rare. Sri Lanka, Cambodia and Burma produce very fine pure Blue Sapphires, although Cambodian Sapphires are sometimes slightly dark. Australian Sapphires tend to have green overtones and concentric hexagonal bands. Midnight Blue Sapphires have traditionally been looked down on but today Midnight Blue Sapphire jewelry is increasingly common - particularly for Sapphire earrings. Intensity, uniformity and purity of color are the most important considerations when making a decision about the purchase of a Blue Sapphire. Fine Blue Sapphires should not contain any overtones or secondary colors, for this will lessen the beauty of this precious gemstone. As the overall beauty of the stone will depend on the cutting, this characteristic must always be taken into consideration. Dark Blue Sapphires will appear black under low light settings, while fine Blue Sapphires will maintain their color in any light setting. Blue Sapphire jewelry remains one of most sought after jewelry types with rings, earrings, pendants and Sapphire necklaces all making not only a beautiful addition to any collection but also a fairly sound investment.

Emerald

So popular as a gemstone has Emerald been (and for so long) that one of the standard gem stone cuts has even been named after the stone which looks its best when cut in that way. The mining of Emeralds has been dated back to more than 3,000 years ago, during the time of the Ancient Egyptian Empire. Emerald bracelets, Emerald earrings and Emerald rings have all been worn and sought after since ancient times. The "green fire" was so mesmerizing and highly valued in the courts of Europe that the Spanish Conquistadors went on a bloody campaign to find the location of the emerald mines in South America. In 1557, the campaign finally ended with the discovery of the spectacular Muzo and Chivor mines in present day Colombia - still the world's major source.

Today Brazil and Zambia produce large quantities of fine Emeralds; however, many still consider Colombian emeralds to be of the highest quality. Very fine emeralds, though in small quantity, are also produced in Pakistan and Zimbabwe. Emeralds of Zimbabwean origin are sometimes called "Sandawana" Emeralds, which refers to the region where the gemstones are mined. Emeralds are made of the base mineral Beryl, with minute traces of chromium and vanadium giving this gemstone the "green fire". Colombian Emeralds are known for their vivid green color, while Brazilian Emeralds are known for their variety of color, ranging from light green to fine medium dark green.

It is quite rare to find emeralds of fine quality over one carat in size, for large Emeralds sometimes contain eye-visible inclusions, known as "jardin" or the "garden". With hardness close to 8 on the Moh's scale, Emeralds are quite durable. However, ultrasonic and steam cleaning could damage the stone, causing fractures. Therefore, only professional jewelers should clean Emeralds. Clarity and transparency are the most important characteristics when evaluating the value of Emeralds. When evaluating from a face up position, very fine quality Emeralds should enable the viewer to see the back facet. The brightness of the gemstone, which is determined by the cutting and the number of inclusions, is also an important evaluation factor. Intense medium green Emeralds command the highest value. The purity of the green color is crucial to the value and the beauty of the stone, with blue or yellow overtones diminishing its value.

Moonstone

Popular with the Romans, who thought it was formed out of moonlight, and in India, where it is considered a sacred stone, moonstone is the most valuable variety of feldspar with an iridescent sheen known as adularescence. A symbol of the Third Eye, moonstone is said to balance yin/yang, protect against epilepsy and sun stroke, cure headaches and nose bleeds, and ensure a high yield in crops. It can help men open their feminine emotional aspects and cool a fever if applied to both temples. During the full moon, men can use it to predict the future by placing it in their mouths but women should avoid it at this time and also when menstruating. A favorite of Art Nouveau jewelers - particularly Moonstone Cats Eye Jewelry, it is a highly prized gift for lovers as it arouses tender passion. It also accentuates the wearer's nature, whether positive or negative.

Moonstone's characteristic shimmer is known as schiller or adularescence, and is caused by the intergrowth of two different types of feldspar with different refractive indexes. Moonstones are usually cut in a smooth-domed cabochon shape to maximize this effect. Moonstones come in a variety of colors, ranging from colorless to gray, brown, yellow, green, or pink. Moonstone cats eye is also available. Clarity ranges from transparent to translucent. Sometimes moonstone will have an eye as well as a sheen. Another related feldspar variety is known as rainbow moonstone. In this variety of labradorite feldspar, the sheen is a variety of rainbow hues. The best moonstone has a blue sheen, perfect clarity, and a colorless body color. Fine moonstone is quite rare and becoming rarer. It is mined in Sri Lanka and Southern India. The rainbow variety can also be found in Madagascar. Blue flash and rainbow moonstones have recently become very popular. Once considered plentiful, they are now rather scarce due to increased demand and prices have risen. Moonstones are often carved into mini art works with "man in the moon" faces popular. The cost of carvings may fall into the moderate category if they are very unusual.

Opal

With "the fire of the carbuncle, the brilliant purple of the amethyst and the sea green color of the emerald, all shining together in incredible union" opal clearly impressed Pliny the Elder (23-79 AD), Roman historian and author of the world's first encyclopedia. The Romans had been wearing opals for centuries and considered them a symbol of hope and purity while for the early Greeks they embodied the powers of foresight and prophecy. The more fancifully minded Arabs thought that opals must have fallen from heaven in flashes of lightning thus achieving their unique play of color or "opalescence". Amazingly this "opalescence" is a result of the 5-10% of water trapped inside the stone in which rows and rows of tiny spheres of silicon dioxide are arranged, diffracting light in a unique fashion. Opal has also featured in literature with Shakespeare referring to it in Twelfth Night as "the queen of gems". Meanwhile, Queen Victoria had to intervene in the near destruction of the 19th century opal market when the writer Sir Walter Scott started a superstition that opals were bad luck for people not born in October. In this novel the heroine owned an opal that burned fiery red when she was angry and turned ashen gray upon her death. Queen Victoria finally dispelled the curse by giving opal jewelry as gifts at a royal wedding. Opal and tourmaline are the official stones for those born in October, and famous French actress Sarah Bernhardt rarely left the house unless adorned with her opalescent birthstone. The physical structure of opal is unique. Tiny spheres of silicon dioxide form a pyramid shaped grid interspersed with water. Tiny natural faults in this grid cause the characteristic "play of color". The effect is similar to the rainbow colors displayed on a soap bubble, only much more dramatic.

Opals vary widely in body color, with white the most common. Black is considered the most valuable as it enhances and accentuates the play of color. Fire opal (yellow, orange or red) is often faceted and can resemble ruby. Green and blue opals are rare.

Opal is sometimes cut with pieces of matrix - the host rock. This strengthens the opal and can also lend a more interesting appearance. The finest examples are Boulder Opal, which sometimes have an undulating surface of "hills" and "valleys". Their unusual shapes and ironstone inclusions make Boulders popular with progressive, modern designers and wearers and are most popular as Opal brooches. Opal pendants, Opal necklaces and Opal earrings are also gaining in popularity.

As opal is relatively soft and fragile it is often made into doublets or triplets backed with plain black opal and fronted with clear quartz. These are ideal for opal rings or any piece that is likely to be receiving rough treatment. Combining body color and play of color we are faced with infinite possibilities, so pricing is complex. Size is also a factor with the carat price for larger stones accelerating accordingly. The intensity of the play of color and the extent to which it covers the opal's surface also count.

Of all the opal taken out of the ground, 95% is valueless "potch" and 95% of the remainder is low quality. Only a mere 0.25% ever makes it to market.

Pearl

Aphrodite's tears of joy, dew drops filled with moonlight, Krishna's wedding gift to his daughter, Cleopatra's love potion. The legends abound but one fact is undeniable, Pearls are the oldest known gem, and for centuries were considered the most valuable. So valuable that the Roman General Vitellius allegedly financed an entire military campaign with just one of his mother's Pearl earrings.

The Romans were particularly enamored of this gem of the sea and Rome's Pearl craze reached its zenith during the first century BC when upper class Roman women (the lower ranks were forbidden from wearing them) wore their pearls to bed so they could be reminded of their wealth immediately upon awakening. They also upholstered couches with pearls and sewed so many into their gowns that they actually walked on their pearl-encrusted hems. The famously excessive Emperor Caligula, having made his beloved horse a consul, decorated it with a Pearl necklace. The first known source of Pearls was the Persian Gulf and the ancients of the area believed that Pearls were a symbol of the moon and had magical powers. Indeed, the oldest known Pearl jewelry is a necklace found in the sarcophagus of a Persian princess who died in 520 BC. The earliest written record of their value is in the Shu King, a 23rd-century BC Chinese book in which the scribe sniffs that a lesser king sent tribute of "strings of pearls not quite round". The Chinese also used pearls in medicinal ways to cure eye ailments, heart trouble, indigestion, fever and bleeding. To this day pearl powder is still popular in China as a skin whitener and cosmetic. In India, pearls were believed to give peace of mind and strength of body and soul. Europeans thought that swallowing whole or powdered pearls cured matters of the mind and heart, and strengthened nerves. Traditionally worn as strings, or set as pendants, today pearl rings are also popular particularly with the rare and unusual black pearls. The Koran states that a good Muslim, upon entering the Kingdom of Heaven, "is crowned with pearls of incomparable luster, and is attended by beautiful maidens resembling hidden pearls". During the Dark Ages, while fair maidens of nobility cherished delicate pearl necklaces, gallant knights often wore pearls onto the battlefield. They believed that the magic possessed by the lustrous gems would protect them from harm. While Queen Isabella had to hock her impressive collection of jewelry to fund Christopher Columbus' expedition to discover the new world, the investment paid off as the discovery of Pearls in Central American waters added to the wealth of Spain. The flood of American Pearls on to the European market earned the newly discovered continent the nickname "Land of Pearls". Unfortunately, greed and lust for the sea gems resulted in the depletion of virtually all the American pearl oyster populations by the 17th Century. But then in 1919, the son of a Japanese noodle maker perfected and patented a method of cultivating Pearls and production of the gems of the sea turned from a treasure hunt into an industry. A natural Pearl (sometimes called an Oriental pearl) forms when an irritant works its way into a particular species of mollusk that is actually closer to a scallop than an oyster. As a defense mechanism, the mollusk secretes a fluid to coat the irritant. Layer upon layer of this coating (known as nacre) is deposited on the irritant until a lustrous pearl is formed. A cultured pearl undergoes the same process. The only difference being that the irritant is a surgically implanted mother-of-pearl bead or nuclei. The best nucleus comes from a Mississippi mussel that only lives in that famed waterway. The core is, therefore, much larger than in a natural pearl. As long as there are enough layers of nacre to result in a beautiful, gem-quality Pearl, the size of the nucleus is of little importance to beauty or durability. Pearls have long been considered ideal wedding gifts because they symbolize purity and innocence. In the Hindu religion, the presentation of an un-drilled Pearl and its piercing has formed part of the marriage ceremony. While in the western hemisphere Pearls are the recommended gift for couples celebrating their third and 30th wedding anniversaries. Almost every Pearl on the market these days is cultured. It's only at antique auctions that you're likely to come across "naturals". Cultured Pearls are still "real" pearls they've simply had a helping hand from mankind. Fakes are usually made from ground fish scales and can be easily detected with the simple tooth test. Gently scrape the pearls along the ridges of your top teeth. If it glides easily, it's fake. If you feel a slight gritty abrasiveness, it's most likely cultured or natural. Saltwater Pearls are usually more expensive than freshwater with Akoya Japanese Pearls the most popular. South Sea Pearls are typically much larger than Akoyas, and if you're buying black then they probably come from Tahiti. Freshwater Pearls are available in a far wider color range than saltwater, including purple, violet, orange, blue and gray. They are cheaper to produce as each mollusk can yield up to 30 pearls per harvest! American freshwaters are allowed to mature for much longer than all other cultured pearls (up to 5 years, compared to 1 year for most others) resulting in a thicker nacre which gives American pearls an unusually high luster and orient (the iridescence from the light reflected from the inside of the pearl). White-pink Pearls with orient attain the highest prices but with the huge variety of colors available today it's best to choose that which compliments your skin tone and hair color. Be sure to check Pearls under several different light sources, against a dark background. Roll the Pearls around to make sure that the luster is uniform throughout. Minor blemishes may be buffed or washed away. Pearls are very porous and will soak up just about any substance they come in contact with, especially perfume and cosmetics.

Peridot

Known by the ancient Egyptians as the “gem of the sun,” peridot has enjoyed a mystical reputation with its alleged powers including: warding off anxiety, enhancement of speech articulation, and success in relationships and marriage. Common in early Greek and Roman jewelry, peridot has been popular since 1500 BC when the Egyptians started mining it on Zeberget, later known as St. John's Island, about 50 miles off the Egyptian coast in the Red Sea. It was a dangerous business back then as the island was infested with poisonous serpents, which a later Pharaoh had driven into the sea. Peridot mining was traditionally done at night when the stone's natural glow is easier to see, the ancient Egyptians even believed that peridots became invisible under the sun's rays.

Hawaiian natives believe peridot is the goddess Pele's tears, while biblical references to the stone include the high priest's breastplate studded with a stone for each of the twelve tribes of Israel, one being peridot. Cleopatra reportedly had a fine collection of “emerald” jewelry, which was really peridot but it was the Ottoman Sultans who gathered the largest collection during their 600-year reign from 1300-1918, with an impressive array of both loose gem stones as well as peridot earrings, peridot rings and other peridot jewelry. Powdered peridot has been used to cure asthma and a peridot placed under the tongue of someone in the grip of a fever will lessen their thirst. Legend has it that drinking from a peridot goblet can increase the potency of medicines. Pirate's believed peridot had the power to drive away evil spirits (and the night's terrors), especially if set in gold. But as protection from evil spirits it must be pierced, strung on donkey hair and worn on the left arm. Possibly the most unusual peridot is that which comes from meteorites called pallasites. Some have even been facetted and set in jewelry, the only extraterrestrial gemstones known to man. Peridot ranges in color from light yellow-green to the intense bright green of new grass to olive. Because of the way peridot splits and bends the rays of light passing through it, it has a velvety, "sleepy" appearance - a shining rich glow, and a slightly greasy luster. The purer green a peridot is, the higher the value. Any tinge of brown greatly diminishes the price as well as visible flaws. In 1994, an exciting new deposit of peridot was discovered in Pakistan, and these stones are among the finest ever seen. The new mine is located 15,000 feet above sea level in the Nanga Parbat region in the far west of the Himalayan Mountains in the Pakistani part of Kashmir. Beautiful large crystals of peridot were found, some that cut magnificent large gemstones. One stone was more than 300 carats!

Rhodolite Garnet

The history of Garnet dates back to the Bronze Age (more than 5,000 years ago), when it was a very popular gemstone. According to Christian and Jewish mythologies, when God's wrath clouded the earth with thunderous storms and endless rain during the Great Flood, a radiant red Garnet guided the way for Noah, ultimately leading his ark to salvation. Unlike other gemstones, Garnets are believed to contain both protective and destructive elements. The Crusaders set Garnets into their body armor, believing the protective power of the stones would lead them to safety. Conversely, some Asian cultures added Garnets to bullets, believing its destructive power would greatly amplify the enormity of a wound.

The name "Garnet" is believed to have derived from "pomegranate" with its red, "Garnet colored" seeds. While the name Garnet has long been associated with a rich red color, the gemstone actually comes in a much wider array of color variations including: reds, oranges, greens and color change.

Garnets are found in a wide variety of locations including: Kenya, Sri Lanka, Thailand, Brazil, India & Arizona (USA), however the bulk of today's Garnet supplies come from Africa. When evaluating Garnets, color is the most important characteristic. The color must be intense and uniform with a tone that is not too light or too dark. Fine Garnets should be eye clean with minimal inclusions under magnification. Size is also a very critical determinant of the stone's value. Garnets are a group of related minerals, containing cubic crystalline structure with slight variations in their chemical compositions. In all, there are 7 major types of Garnets, which include Almandine, Pyrope, Spessartine, Grossular, Andradite, Rhodolite and Malaia. Many consider Rhodolite to be the "Queen of Garnets", due to its delicate pink to violet red color, reminiscent of the rhododendron flower (a common symbol of feminine beauty). Chemically, this Garnet's composition is a blend of Almandine and Pyrope. The most spectacular pink Rhodolites are mined in Sri Lanka, Tanzania and Zimbabwe.

Tanzanite

The showcase of this newly discovered gemstone by Tiffany & Co. in 1967 captured the world's attention and has held it in its thrall ever since with Tanzanite becoming the most popular gem stone in the world today after the “Big Four” (diamond, ruby, sapphire, & emerald). It is believed that the Masai herders were the first people to discover this gemstone. According to popular myth, a lightning strike near the Merelani hills set surrounding grasslands on fire. When the Masai herders returned to the area with their livestock, magical blue stones appeared on the ground. When a Portuguese geologist, named DeSouza, traveled to this area in Tanzania, he saw the magnificent blue stone and assisted Tiffany & Co. in introducing this exciting discovery to the world. With vast deposits in the northern part of the country near the Merelani hills, Tanzania is the primary commercial source of tanzanite. Very small deposits have been found in Kenya, but were not considered large enough for commercial purposes. Until recently.

With Tanzanite's ongoing popularity even these small deposits are now being mined and have even been the source of armed disputes. When heated to 600 degrees Celsius, greenish to brownish zoisite undertakes an incredible metamorphosis, resulting in the creation of this vibrant blue to blue violet gemstone, Tanzanite. With hardness between 6 and 7 on the Moh's scale, Tanzanite is quite fragile, and for this reason, ultrasonics should never be used to clean this precious gem stone. However with an appropriate setting and some care, all kinds of tanzanite jewelry including Tanzanite rings will provide their wearer's with endless pleasure. Dazzling as Tanzanite earrings and Tanzanite necklaces, this rare gemstone speaks volumes about the wearer's personality and sense of style.

In its early discovery, Tanzanite was only available in small stones; however, today, larger stones have been made available, providing greater variety to the gemstone market. The lighting condition is the most critical factor when evaluating the value of these gem stones. Tanzanite will display the most blue under daylight, while the violet shade will be more apparent under incandescent light. The stone which commands the highest value is generally the one which displays minimal violet, even when it is viewed under incandescent light. It is common to find flawless tanzanite crystals; therefore, the stone should not contain too many inclusions.

Tourmaline

As it is found in all spectrums of color, Tourmaline is often described as the "chameleon gemstone". It is not surprising to find a fine tourmaline that mirrors the exact semblance of other gemstones, such as emerald, ruby and sapphire. Some tourmaline crystals may even appear as crystallized rainbows with several bands of color, ranging from the most brilliant red to the deepest blue. Many refer to tourmaline as the "muses' stone", for they believe that its imaginative colors contain inspirational powers which enable the mind of its beholder to bring forth illimitable vision and creativity. During the Manchu Dynasty in China, members of the Mandarin class wore round buttons made of red tourmaline, distinguishing themselves from other classes of citizens. Dowager Empress Tzu Hsi was so fascinated by tourmaline's beauty and color that she had over one ton of these precious gem stones in her royal collection. The name tourmaline is believed to have derived from the Sinhalese word, "turmali", meaning "mixed". With a hardness of 7-7.5, this multitudinous gem is ideal for all types of jewelry setting. Tourmaline earrings, tourmaline necklaces, tourmaline rings and other types of tourmaline jewelry are all well-suited to everyday wear and with its relatively affordable price and the variety of colors available, tourmaline is the perfect gem for those who like to showcase a variety of exquisite jewels.

Tourmaline comes in all spectrums of color, the most common being green and pink. The red variety is often referred to as "rubellite", as its vibrant red color often resembles that of the finest rubies. A rare green chrome variety of tourmaline found in Tanzania is also available, but in small quantities. An extremely rare variety is the Paraiba tourmaline. Found in Brazil, this gemstone exhibits very intense neon-like blue and blue-green colors. Its color is often comparable to the spectacular blue of the finest sapphires. Some tourmaline gems may contain two or more distinctive colors and are commonly known as bi-color, tri-color or parti-color tourmalines.

Tourmaline is available in all sizes ranging from small to over 100 carats; however, stones of a rare color are often found only in smaller sizes. For example it is extremely uncommon to find fine rubellites over 20 carats in weight. Some color varieties of tourmaline are more included than others. For example it is common to find bi-color and multi-colors stones with visible inclusions.

Similar to the evaluation of other precious stones, the intensity of color and the clarity of the gemstone are the most important considerations. Green chrome and Paraiba tourmalines are the most expensive color varieties, due to their spectacular beauty and rarity. Fine rubellites and multi-color stones will command moderate to high prices depending on the intensity of their color and the existence of eye visible inclusions.

Gemstone Guide

Agate

Amethyst

Ametrine

Aquamarine

Blue Sapphire

Citrine