Megan's Fun Facts: Colored Stones from Brazil -- EMERALD

Emeralds have the most beautiful, intense and radiant green color imaginable. Known as the birthstone for May and the traditional gift for the 20th and 35th wedding anniversary stone, the green color represents life, renewal, harmony, beauty and constant love.

Part of the beryl family, the emerald has traces of chromium and vanadium which are responsible for the fascinating color. Normally, these two elements are concentrated in different parts of the Earth's crust to beryllium, so the emerald should, strictly speaking, not exist at all. But during intensive tectonic processes such as orogenesis, metamorphism and erosion of the land, these contrasting elements found each other and crystallized out to make one of our most beautiful gemstones.

The emerald’s hardness protects it from scratches, but its brittleness and many fissures can make cutting, setting and cleaning rather difficult. The high value of the raw crystals and the frequent inclusions makes cutting emeralds especially challenging. Gem cutters have developed a special cut just for this gem, naturally, called the emerald cut. The clear design of this rectangular or square cut with its beveled corners brings out the beauty of this valuable gemstone and protects it from mechanical strain.

Today, many emeralds are enhanced with colorless oils or resins. This is a general trade practice, but it does have the consequence that they react very sensitively to inappropriate treatment. For example, they cannot be cleaned in an ultrasonic bath. The substances that may have been used by the cutter during his work, or applied subsequently, seal the fine pores in the surface of the gem. Removing them will end up giving the stone a matte appearance. For this reason, emerald rings should always be taken off before hands are submerged in water containing cleansing agent.

Only seldom will a large emerald with good color and good transparency be found. That is why fine emeralds are so valuable. In top quality, fine emeralds are even more valuable than diamonds.

One of the world's largest is the so-called 'Mogul Emerald'. Found in 1695, it weighed 217.80 carats and was 10cm tall. Prayer texts are inscribed on one side and magnificent floral ornaments on the other side. This legendary emerald was auctioned by Christie's of London to an unidentified buyer for $2.2 Million on September 28, 2001.

Brazil is one of the largest volume producers of emerald in the world, and the states of Minas Gerais, Bahia, and Goias have the largest deposits in the country. Significant emerald deposits in Minas Gerais are found at the Capoeirana mine and Itabira mine in Nova Era, Municipio Itabira. Brazil has been known to produce large rough emeralds up to 200 carats in size.

Megan's Fun Facts: Colored Stones from Brazil -- AMETHYST

Amethyst – known to many to be a stone for friendship - is the birthstone for February and represents the 6th wedding anniversary. Gemstone therapists say that the amethyst has a sobering and cleansing effect. In popular belief, the amethyst offers protection against drunkenness - for the Greek words “amethystos” mean “not intoxicated”. In earlier times, people liked to drink wine from amethyst cups, which explains the stone's protective function against alcoholism. Its purple color made it a stone of royalty for many thousands of years.

Amethyst is the most valued member of the quartz family. It displays a range of shades from deep purple, light lilac, lavender and mauve. Amethyst may exhibit one or both secondary hues of red and blue. Top quality amethyst is considered a deep medium purple with rose-colored flashes. The ideal grade is called "Deep Siberian" and has a primary purple hue of around 75–80%, with 15–20% blue and (depending on the light source) red secondary hues.

Green quartz is sometimes called green amethyst. Other names for green quartz are prasiolite, vermarine or lime citrine. Amethyst generally becomes yellow when exposed to heat. Much of the citrine, cairngorm and yellow quartz is said to be "burnt amethyst". Sudden changes of temperature can also be harmful to the stone.

In the 19th century, the color of amethyst was attributed to the presence of manganese. Recent studies have shown a complex interplay of iron and aluminum is responsible for the color. When manganese is present in clear quartz, amethyst is produced. The amount of iron contained in the specimen accounts for the depth of purple color. The amethyst has its hardness, moderate refraction and weight in common with the other quartzes, but the crystal structure is different, and most unconventional. The construction is stratified, as a result of which areas and lamellae of varying color intensity often come about. This explains why there are relatively few large cut amethysts of an evenly distributed dark color.

Amethyst is produced in abundance from the Brazilian state of Minas Gerais where it occurs in large geodes (“amethyst-grotto”) within volcanic rocks. Brazilian state Rio Grande do Sul is a large world producer exceeding in quantities of Amethyst. Most of the material from Brazil is light-colored and tender purple.

Megan's Fun Facts: Colored Stones from Brazil -- TOURMALINE

Tourmaline is a crystal silicate mineral compounded with elements such as aluminum, iron, magnesium, sodium, lithium, or potassium. Tourmaline is classified as a semi-precious stone and the gem comes in a wide variety of colors. No two tourmalines are exactly alike. Usually, iron-rich tourmalines are black to bluish-black to deep brown, while magnesium-rich varieties are brown to yellow, and lithium-rich tourmalines are almost any color: blue, green, red, yellow, pink etc. Rarely, it is colorless. Bi-colored and multicolored crystals are common, reflecting variations of fluid chemistry during crystallization. Crystals may be green at one end and pink at the other, or green on the outside and pink inside: this type is called watermelon tourmaline. Some forms of tourmaline are dichroic, in that they change color when viewed from different directions.

Almost every color of tourmaline can be found in Brazil, especially in the Brazilian states of Minas Gerais and Bahia. In 1989, miners discovered a unique and brightly colored variety of tourmaline in the state of Paraíba. The new type of tourmaline, which soon became known as "paraiba tourmaline", came in unusually vivid blues and greens. These colors were often described as "neon" since they appeared to glow. Brazilian paraiba tourmaline is usually heavily included. Much of the paraiba tourmaline from Brazil actually comes from the neighboring state of Rio Grande do Norte. Material from Rio Grande do Norte is often somewhat less intense in color, but many fine gems are found there. It was determined that the element copper was important in the coloration of the stone.

Tourmalines are known as October’s birthstone, and are gifted for the 8th wedding anniversary.

Megan's Fun Facts: Colored Stones from Brazil -- TOPAZ

Topaz is made up of fluorine, aluminum and silicate and is found in many colors and can be colorless, much like diamonds.

Pure topaz is colorless and transparent but is usually tinted by impurities. Topaz is typically found in the colors wine, yellow, pale gray or reddish-orange, blue brown. It can also be made white, pale green, blue, gold, pink (rare), reddish-yellow or opaque to transparent/translucent.

Orange topaz (“Precious Topaz”) is the traditional November birthstone, the symbol of friendship, is also the state gemstone for Utah.

Imperial topaz is yellow, pink (rare, if natural) or pink-orange. Brazilian Imperial Topaz can often have a bright yellow to deep golden brown hue, sometimes even violet. Many brown or pale topazes are treated to make them bright yellow, gold, pink or violet colored. Some Imperial topaz stones can fade on exposure to sunlight for an extended period of time. This beautiful stone symbolizes the stone given for the 23rd wedding anniversary.

Mystic topaz is colorless topaz which has been artificially coated giving it the desired rainbow effect.

Blue topaz is the state gemstone for Texas, the modern birthstone for December and represents the 4th wedding anniversary. Naturally occurring blue topaz is quite rare. Typically colorless, gray or pale yellow and blue material is heat treated and irradiated to produce a more desired darker blue color.

In mysticism, the topaz is attributed with a cooling, styptic and appetizing effect. It is said to dispel sadness, anger and nocturnal fears. The Orange topaz is said to symbolize courage, fidelity, wisdom and serenity. The Blue topaz is said to symbolize success, love, luck, happiness and prosperity.

Topaz mining in Brazil dates back to the 1700s. Imperial Topaz was originally mined in the “topaz belt” of Minas Gerais, near the mining town of Ouro Prêto.

Megan's Fun Facts: Colored Stones from Brazil -- AQUAMARINE

Aquamarine, March’s birthstone, is said to symbolize courage, creativity, health, perception and hope. The blue of aquamarine is a divine, eternal color and represents the color of the sky. This beautiful stone also symbolizes the stone given for the 19th wedding anniversary.

Iron is the substance which gives aquamarine its color, a color which ranges from an almost indiscernible pale blue to a strong sea-blue. As the color intensifies, the more expensive the gem becomes. Some aquamarines have a light, greenish shimmer. However, it is the pure, clear blue that continues to epitomize this beautiful gem. Its light blue arouses feelings of sympathy, trust, harmony and friendship.

Aquamarine is almost entirely free of inclusions. This gem has a hardness which makes it very tough and helps protect from scratches. The rare, intense blue aquamarines from the Santa Maria de Itabira mine in Brazil are called 'Santa Maria'. The 'Espirito Santo' from the Brazilian state of that name is known as a lighter blue aquamarine. The finest Brazilian aquamarine comes from the Marambaia Valley, north of Teófilo Otoni, located in Minas Gerais, Brazil.

Significant aquamarine finds in Minas Gerais include the near-flawless 244 lbs, 552,500 carat Papamel Aquamarine. This aquamarine was found in 1910 from the Papamel mine (also known as Batadal mine) along the Marambaia River, 12 miles east of the village of Ponto de Marambaia.

Megan's Fun Facts: MINING IN BRAZIL

MINING IN MINAS GERAIS, BRAZIL



The state of Minas Gerais is one of 26 Brazilian states, located on the western side of the Southeastern Subdivision. The name Minas Gerais ("General Mines") refers back to the 18th and 19th centuries, when large mines produced gold and precious stones in the state. Minas Gerais still produces about 80% of Brazil's precious gems and minerals, including emerald, alexandrite and topaz.

The cities of Governador Valadares and Teófilo Otoni to the north-east, have established themselves as major hubs of the gem-trading industry, due to their proximity to some of the richest gem mines. Minas Gerais is rich in quantities of aquamarine, chrysoberyl, emerald, kunzite, morganite, tourmaline and topaz.

BRAZILIAN GEM SHOW: Saturday, October 23rd