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...

Rare Earth Elements (REE) and its unique properties

 

Rare Earth Elements

Rare earth elements (REEs) are a group of chemical elements that are essential in various industries due to their unique properties. Here are some of the rare earth elements and their uses:

ElementUses
ScandiumAlloying agent in aerospace components, improves the performance of solid oxide fuel cells, enhances the properties of aluminum alloys, used in high-intensity discharge lamps, used in sports equipment like baseball bats and bicycle frames for its lightweight and high-strength properties
YttriumUsed in superconductors, phosphors for color televisions, lasers, and solid-state lasers, catalysts in petrochemical refining, and as a component in ceramics and glass
LanthanumUsed in hybrid car batteries, camera lenses, high-refractive-index glass, catalysts in the petroleum industry, and as a component in ceramics and glass
CeriumUsed in catalytic converters, self-cleaning ovens, polishing agents, and as a component in glass, enamels, and ceramics
PraseodymiumUsed in magnets, lasers, alloys for aircraft engines, and as a component in ceramics and glass
NeodymiumUsed in magnets, lasers, headphones, microphones, and as a component in ceramics and glass
PromethiumUsed in nuclear batteries, thickness gauges, and luminous paint
SamariumUsed in magnets, lasers, neutron capture therapy for cancer treatment, and as a component in ceramics and glass
EuropiumUsed in phosphors for color televisions, fluorescent lamps, and as a component in ceramics and glass
GadoliniumUsed in magnetic resonance imaging (MRI), neutron capture therapy for cancer treatment, and as a component in ceramics and glass
TerbiumUsed in phosphors for color televisions, fluorescent lamps, lasers, and as a component in ceramics and glass
DysprosiumUsed in magnets, lasers, nuclear reactors, and as a component in ceramics and glass
HolmiumUsed in magnets, lasers, nuclear reactors, and as a component in ceramics and glass
ErbiumUsed in lasers, fiber-optic communication systems, and as a component in ceramics and glass
ThuliumUsed in lasers, portable X-ray devices, and as a component in ceramics and glass
YtterbiumUsed in lasers, atomic clocks, and as a component in ceramics and glass
LutetiumUsed in catalysts, phosphors, and as a component in ceramics and glass

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