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Showing posts from December, 2021

Gemstone Windows and Dark Patches: What to Look for in a Cut Gem

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AI-generated educational illustration. Conceptual only; not a photograph of an actual specimen or location. A coloured gem may have a pale, see-through centre or areas that look almost black. Both affect its appearance, but they do not have the same cause. What is a window? A window is an area where light passes through the gem instead of being returned towards the viewer. You may see the background through it, especially near the centre. Cutting angles and the material's refractive index—how it bends light—help determine whether this happens. There is no single ideal depth for every gemstone. Why dark patches need a closer look Darkness can have several causes. The material may absorb a lot of light. Some facets may reflect dark surroundings or the observer. Extinction is another cause, involving light that is not returned to the viewer after internal reflection. For that reason, calling every black patch “extinction” can be misleading. A simple viewing routine Look at the gem fac...
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Gemology Hub`: Natural Sapphire Inclusions There are several type...

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Gemology Hub`: Natural Sapphire Inclusions There are several type... : Natural Sapphire Inclusions There are several types of inclusions in natural sapphires. • Needles. These are mineral inclusions that are lon... Related articles Inclusions in corundum Unheated Corundum (Ruby & Sapphire) Inclusions Ruby and Sapphire (corundum)
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Optic fiber or fiber optic or man mand cat's glasses and their identification

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  Optic fiber or fiber optic or man made glasses  come in a variety of different colors with a sharp cat's eye effect which imitat the natural gems for chrsoberly  Man made cat's eye glass  when you see  through the side view of the cabochons  you will find  hexagonal prismatic wax (honeycomb like pattern) as shown in the picutres below.  honeycomb-like pattern in optical fiber glass honeycomb-like pattern in optical fiber glass honeycomb-like pattern in optical fiber glass Related articles Chrysoberyl Basic Terms used in Gemology Standard Gemological Instruments and their use
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Location: United States
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Requirement for a well-equipped gemological laboratory for analysing gemstones/diamonds

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  Establishment of    well equipped Gemological laboratory   For Gemstones / Diamond   Testing Certification 1.      Natural Gemstones samples e.g Emerald, ruby, sapphire (Cut/rough) 2.      Treated gemstones samples (dyeing, filling, heat treated etc) 3.      Composite stones (double/triplet) 4.      Synthetic gemstones samples (made by all manufacturing process such as flux, flame fusion etc.) 5.      Natural diamonds 6.      Treated diamonds (HPHT, glass or wax filling , irradiated etc) 7.      Synthetic diamonds 8.      Diamond Imitation stones (CZ, GGG) etc 9.      Master stones of diamonds (For diamond color Grading) 10.                         En...
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Location: Peshawar, Khyber Pakhtunkhwa, Pakistan
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What is the definition of hardness? What is the Hardness Scale? How is it used in mineral testing?

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  Hardness Scale (Friedrich Mohs Scale) T he b o nds h o lding at o ms t o gether determine a mineral's hardness. In 1812, the Austrian mineral o gist Friedrich M o hs devised a scale  of hardness that is still in use t o day. He selected ten minerals as   standards and arranged them s o that any mineral o n  the scale  w o uld scratch o nly th o se bel o w it. Everyday o bjects can be used   t o   test where a mineral fits int o the scale. A fingernail has a hardness   o f 2.5, and a penknife is 5.5. Minerals o f six and ab o ve   will scratch   glass; glass will scratch apatite and o ther minerals   bel o w it. Mohs hardness scale  The Mohs Scale of Hardness Explained Related articles What is gemstone? define beauty , rarity and durability in gemstone. Physical Properties of corundum What is mineral?
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Your diamond will be as unique as you are because of the inclusions.

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 You can claim your stolen diamond based on the inclusions. Have you ever wondered why jewellers use special magnifying lenses to examine diamonds? They're looking for things to include. Inclusions, often known as faults, are internal characteristics of the stone that can only be seen when magnified. The size and kind of inclusions in a diamond determine its clarity. Because imperfect diamonds are uncommon and expensive, the majority of loose stones, engagement rings, and other jewellery available includes some defect. An inclusion is similar to a freckle on your fiancé's nose; it's not a defect because it adds character to your diamond. INCLUSIONS OF DIFFERENT KINDS T he majority of gemstones sold in jewellery stores are imperfect; they may have a variety of flaws. The following are the most prevalent forms of diamond inclusions: Crystals  Natural, uncooked minerals that form crystals are included within certain diamonds. This form of inclusion is often invisible to the hu...
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Synthetic Diamonds: A Brief History

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  Synthetic Diamonds: A Brief History In the early part of the twentieth century, several attempts to synthesise diamond were conducted, and by the 1940s, the temperature and pressure parameters under which diamond is the stable phase of carbon had been established experimentally. Berman and Simon expanded on these findings. Graphite is the stable phase at normal temperatures and pressures, which is interesting. At normal temperature and standard atmospheric pressure, diamond, the ultimate gemstone, is merely meta-stable! Fortunately, converting a diamond to graphite requires a lot of energy, and in an inert atmosphere, a diamond may be safely heated to at least 1500 °C without causing harm. When the temperature rises beyond 1800 °C, however, the material quickly transforms into graphite. Following the availability of tungsten carbide in the 1930s, serious attempts to synthesise diamond started. This exceptionally strong material enabled the development of pressure cells capable of...
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