subject: Optical Properties Of Gems - Gems, Jewelry, Jewelry - Jewelry Industry - Pneumatic Butterfly Valve [print this page] Gemstones optical properties of minerals, including transparency, gloss, color, dispersion, pleochroism, and some special optical effects, which are gems of the visible light absorption, reflection, transmission, refraction, interference, scattering, and diffraction effect caused by the chemical composition with precious stones, crystal structure, aggregate structure closely related, it is a gem identification, evaluation of important content.
Transparency and gloss jewel Transparency?? Is the light through the gem of the program, the chemical composition with precious stones and structures. The general transparency of gem can be divided into three categories:
Clear: The stones can be more clearly seen behind the objects, such as crystal, diamonds, etc.;
Translucent: some light through crystal, but not perspective on the back of objects, such as high-quality jade, moonstones, etc.;
Opaque: light basically can not, such as malachite.
Gloss?? Is the ability to reflect light gem surfaces, and its intensity is just the opposite of transparency, transparent gem gloss weak. The precious stone can be divided into:
Metallic luster: highly reflective, like a shiny surface plating general, such as hematite;
Semi-metallic luster: strong reflection, such as magnetite;
Diamond Gloss: The surface reflectance was stronger than glass, and a brilliant bright feeling, such as diamonds;
Shiny glass: only a small part of the reflection of light, such as glass, crystal, topaz, etc.;
Oil sheen and gloss resin: the surface like a grease-like reflectors (such as Crystal's fracture) and similar resin reflective surface (such as the amber of the fracture);
Waxy luster: the reflective, such as serpentine jade class;
Pearl luster: such as pearl-like reflection of light with soft and colorful;
Silk gloss: like a silk-like reflective, as the fibrous aggregation of precious stones (such as tiger eye stone) specific.
1, gem color, multicolor and dispersion
Length of visible light by light is divided into red, orange, yellow, green, green, blue, purple band, the color is the jewel of the absorption of different wavelengths of visible light reflection of different levels. If a gem on the white in the blue and green light absorption, the gem is red hue, it is the result of the remaining mixture of light waves, also known as subtractive. To accurately observe the gem's color, must be the standard in natural light or under white light, be light to avoid causing false colors. In addition to color, the gem was also used to study the saturation and brightness of the term: bright color saturation means a positive correlation between the degree. Same as emerald and malachite green hue, but the former than the latter to be more bright. Brightness of the brightest color it with the gem itself, the optical properties and processing quality of the. Rare colored gemstones are often asked to pure tone, saturation and high brightness.
Polychroism?? That because of non-homogeneous anisotropic sapphire crystal in different directions to show these characteristics in different colors, two colors and three colors of the points. Such as sapphire crystal along the direction of the Director of its cylinders were blue and green, blue vertical extension direction, and are thus dichroism; multicolor gemstones strong eye can discern, but most require special gem pleochroism of equipment (such as two-color mirror) be observed.
Dispersion?? That natural light slanting into a medium of light generated when the decomposition of phenomena such as the decomposition of sunlight with a prism into the seven colors can the same reason. Sato will result after the dispersion of precious stones, but the extent of production due to the refractive index of gemstones differ. Each gem can cause dispersion of the capacity as the gem of the dispersion degree, such as diamonds and high dispersion, to produce a brilliant luster, is dazzling; crystal dispersion degree is lower.
