Stone Info_Emerald.pdf

***Emerald*** LARGEST CONSUMERS : US, Europe, Colombia, Brazil MOHS SCALE: 7.5 to 8 VARIETY/ SPECIES/GROUP : Variety: Beryl COLOR/HUE RANGE/VALUE: most prized emeralds are highly transparent, most desirable colors are bluish green to green, with strong to vivid saturation and medium to medium-dark t...

***Emerald*** LARGEST CONSUMERS : US, Europe, Colombia, Brazil MOHS SCALE: 7.5 to 8 VARIETY/ SPECIES/GROUP : Variety: Beryl COLOR/HUE RANGE/VALUE: most prized emeralds are highly transparent, most desirable colors are bluish green to green, with strong to vivid saturation and medium to medium-dark tone, It’s a purer green color when iron content is relatively low.(aka less blue) (hue is too yellowish or too bluish, the stone is not emerald, but a different variety of beryl) CHEMICAL COMPOSTION: Trace Elements: chromium, vanadium, iron beryllium, aluminum, silicon, oxygen, and one or more of the trace elements FORMING SOURCE : metamorphic-rock environments, where pegmatites intersect with schists (Like in Brazil), but can occur in either metamorphic or sedimentary rock, Colombia is a sedimentary rock environment. Its emeralds are associated with hydrothermal veins. CRYSTAL STRUCTURE: elongated six-sided prism POSSIBLE PHENOMENA: Dichroism (If the cutter orients the table perpendicular to the crystal’s length, the cut gem’s face-up color is the prized bluish green) CLARIETY CHARACTERISTICS: color zoning, fractures, liquid and multiphase inclusions, mineral crystals, needles, and growth tubes. trapiche emerald has dark inclusions that extend from the center of the crystal, forming a pattern that looks like the spokes of a wheel, “oil-drop effect,” occurs in the finest Colombian emeralds -A roiled pattern similar to honey or oil. GIA's notes “clarity enhanced” at minor, moderate, or significant (stated as F1, F2, and F3) levels. COMMON TREATMENTS: oiling or fracture filling ( cedarwood oil which is a natural resin) dyeing COMMON CUTS : Emerald cut ( which allows for minimum eight lose) round, oval, pear, marquise, or heart shapes, in brilliant, step, or mixed-cut facet arrangements, as well as cabs, a strong market of calibrated sizes 5x3 mm through 7x5 mm range. Calibrated rounds are available in sizes below 4 mm. TRADE NAMES : “Colombian” is commonly used to describe the finest emerald color, “Zambian” is often are slightly darker & more bluish than Colombian emeralds, and often have higher clarity, “jardin" is used to describe inclusions COUNTRIES OF ORIGIN : Colombia, Zambia, Brazil, and the Central Asian countries of Afghanistan and Pakistan supply the great majority of emeralds on the international market. \The Kagem mine, operated by Gemfields, is by far the largest, best-funded, and most productive emerald mine in Zambia and most likely the world, Russia, Zimbabwe, Madagascar, and China are among the world’s other commercial emerald sources. MAIN SYNTHETIC PROCESS: flux and hydrothermal, with hydrothermal the primary method, Jacques Joseph Ebelman was the first to use the flux process to synthesize emerald crystals, In 1960 Johann Lechleitner synthesized emerald hydrothermally. Tairus supplier of both hydrothermal and flux-grown synthetic emeralds out of Russia COMMON IMITATION MATERIAL: Colored glass is frequently used, quench-crackled and dyed quartz,synthetic spinel triplets, green synthetic cubic zirconia (CZ), green yttrium aluminum garnet (YAG), CUTTING/ TRADE CENTER: Colombia cuts most of its own production (especially the highest-value goods) and cutting and treatment take place in Bogotá, lower-quality material is sold to Jaipur cutting operations, Brazil also cuts higher-quality material domestically and sells lower-quality material to manufacturers in Jaipur, In Zambia, Gemfields created a structured auction system