Alexandrite World Occurrences and Mining Localities
Chromium is also the trace element that makes berylemerald’s green. Alexandrite is purplish red in incandescent light or candlelight. Alexandrite is bluish green in daylight or fluorescent light. The largest uncut gem-quality alexandrite specimen ever found is the Sauer Alexandrite that weighs 122,5400 carats and was found in Bahia, Brazil, in 1967. Natural alexandrite is rarer than diamonds and more costly than emerald, ruby, and sapphire. Alexandrite is now mined in parts of Africa, Brazil, and Sri Lanka although the gem is still extremely rare and valuable.
Cat’s eye material is found as a small percentage of the overall chrysoberyl production wherever chrysoberyl is found. If the pegmatite fluid is rich in beryllium, crystals of beryl or chrysoberyl could form. Beryl has a high ratio of beryllium to aluminium, while the opposite is true for chrysoberyl. For alexandrite to form, some chromium would also have had to be present.
However, beryllium and chromium do not tend to occur in the same types of rock. Chromium is most common in mafic and ultramafic rocks in which beryllium is extremely rare. Beryllium becomes concentrated in felsic pegmatites in which chromium is almost absent. Therefore, the only situation where an alexandrite can grow is when Be-rich pegmatitic fluids react with Cr-rich country rock.
Translucent yellowish chatoyant chrysoberyl is called cymophane or cat’s eye. Cymophane has its derivation also from the Greek words meaning ‘wave’ and ‘appearance’, in reference to the haziness that visually distorts what would normally be viewed as a well defined surface of a cabochon. In this variety, microscopic tubelike cavities or needle-like inclusions of rutile occur in an orientation parallel to the c-axis, producing a chatoyant effect visible as a single ray of light passing across the crystal. This effect is best seen in gemstones cut in cabochon form perpendicular to the c-axis. The color in yellow chrysoberyl is due to Fe3+ impurities. The alexandrite variety displays a color change dependent upon the nature of ambient lighting.
When Nordenskiöld first found alexandrite in Russia, he thought the stone was an emerald. Alexandrite is part of the chrysoberyl family along with chrysoberyl, also known as cat’s-eye. The first mines in Deobhog began to produce some alexandrite in 2000 and currently producing the bulk of today´s alexandrite, but the focus of the current mining is in Andrha Pradesh province near the city of Vishakhapatnam. Get DIY project ideas and easy-to-follow crafts to help you spruce up your space. The Alexandrite is honoured to be featured in the May 2021 issue of British VOGUE. British VOGUE is one of the world’s most coveted fashion magazines and one of the most influential of all Vogue publications.
- Natural alexandrite is rarer than diamonds and more costly than emerald, ruby, and sapphire.
- Spinels sometimes show a blue to violet color change but the change is usually weak and the stones never look like alexandrite.
- Alexandrite Encyclopedia is a non-commercial guide for people interested in learning more about the history, gemology and valuation of alexandrite gemstones.
- Stones over 0.75 ct. that meet the strict quality control requirements set forth by Mark Henry are extremely difficult to obtain.
It is a very costly process, so this type of synthetic https://cryptolisting.org/ is still very expensive. Pricing of Alexandrite is based primarily on the strength of the color change and the purity of the hue. Any alexandrite more than three carats is highly uncommon. Smaller stones are more readily available to commercial jewelers. French mineralist Nils Gustaf Nordenskiöld discovered alexandrite in the Ural mountains of Russia in 1834.
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While the color change is not as dramatic as some of the finer Russian alexandrite, it is can still be very pronounced. Some gemstones falsely described as lab-grown synthetic alexandrite are actually corundum laced with trace elements (e.g., vanadium) or color-change spinel and are not actually chrysoberyl. As a result, they would be more accurately described as simulated alexandrite rather than “synthetic”.
Chrysoberyl is the third-hardest frequently encountered natural gemstone and lies at 8.5 on the Mohs scale of mineral hardness, between corundum and topaz . However, it is the color change garnets especially the ones from Bekily in Madagascar that most resemble What is Alexandrite. The stones are actually a mixture of pyrope and spessartite and can show several colors depending on the light source. Size is another important factor since alexandrite stones in larger karat sizes are extremely rare, making them more in demand. Clarity and transparency are often overlooked so long as the stone is large and exhibits an impressive color change. This rare and expensive gemstone is hard to find in your everyday jewelry store, despite being named the official birthstone of June.
Consider obtaining a gem report to reveal a stone’s true origins before spending a large amount of money on alexandrite that’s advertised as natural. Alexandrite is rated at 8.5 on the Mohs scale, between diamond at 10 and corundum at 9. Most desirable alexandrite is transparent but may have inclusions that appear under magnification as small spots or fine threads. Less desirable alexandrite found today may be translucent or opaque. Please accept my sincerest appreciation for the honesty and integrity that you demonstrated in working with my wife on this sale. I have never owned a quality piece of jewelry such as this – fit and finish are amazing.
The year alexandrite was discovered in Russia’s Ural Mountains. An interesting feature of its crystals are the cyclic twins called trillings. These twinned crystals have a hexagonal appearance, but are the result of a triplet of twins with each “twin” oriented at 120° to its neighbors and taking up 120° of the cyclic trilling. If only two of the three possible twin orientations are present, a “V”-shaped twin results.
It shines bluish-green to reddish-purple when exposed to different light sources and is transparent when faceted. It is a rare and beautiful stone, much sought after by collectors and healers alike. Alexandrite is not temperamental gemstone, but because of its value, it should be diligently cared for. To clean alexandrite jewelry at home, use a soft brush and a solution of warm and gentle dish detergent. Clean the gemstone thoroughly to remove any dirt or oils that can affect the gemstones brilliance.
ALEXANDRITE: June Birthstone
The remnant magma thus becomes richer in water, and also in rare elements that similarly do not fit in the crystal structures of major rock-forming minerals. The water extends the temperature range downwards before the magma becomes completely solid, allowing concentration of rare elements to proceed so far that they produce their own distinctive minerals. The high water content of the magma made it possible for the crystals to grow quickly, so pegmatite crystals are often quite large, which increases the likelihood of gem specimens forming. Most gemological laboratories only identify gemstones, they do not appraise them. Although the daylight colors are usually somewhat muddy, they can be very red under incandescent light and do look similar to some of the alexandrites from the same country.
I adore my ring, it makes me smile every time I look at it, and I never fail to be amazed at the different permutations of color depending upon the light source – it never seems to be the same ring twice! Thanks again, Luis, for your continued kindness and exemplary customer service. Emerald Emerald is the bluish green to green variety of beryl, a mineral species that includes aquamarine. Explore sources, gemological research, and the role of gems in history. Larger, higher-quality gems rise in price dramatically.
Chrysoberyl forms as a result of pegmatitic processes. Melting in the Earth’s crust produces relatively low-density molten magma which can rise upwards towards the surface. As the main magma body cools, water originally present in low concentrations became more concentrated in the molten rock because it could not be incorporated into the crystallization of solid minerals.
The synthetic versions change color in much the same way as natural alexandrite but often have more internal irregularities than the natural stones. Air bubbles are sometimes visible in synthetic alexandrite, depending on the method used to create the stones. Fine alexandrites or alexandrite jewelry can be purchased from jewelers specializing in colored gemstones, at trade shows, at high end jewelry auctions, or online from websites specialized in alexandrite. There is a dramatic rise in value for ‘eye clean’ gemstones as visible inclusions will affect the light inside the gemstone and impair the color change. Currently, the mines in Brazil are yielding some of the cleanest specimens of Alexandrite found on Earth. Gems lacking the silky inclusions required to produce the cat’s eye effect are usually faceted.