Exam (elaborations) Colored Stone

COLORED STONE️️Any gem material other than diamond. GEMOLOGY️️The study of gems. ORGANIC️️Once living, or produced by a living organism (plant or animal). MINERALS️️A natural, inorganic substance with a characteristic chemical composition and usually characteristic structure. INORGANIC️️Composed of, or arising from, non-living matter. CHEMICAL COMPOSITIONS️️Kinds and relative quantities of atoms that make up a material. DURABILITY️️A gemstone's ability to withstand wear, heat, and chemicals. LUSTER️️The appearance of a material's surface in reflected light. TRANSPARENCY️️Degree to which a material allows light to pass through it. HARDNESS️️How well a gemstone resists scratches and abrasion. TOUGHNESS️️How well a gemstone resists breaking, chipping, and cracking. STABILITY️️How well a gemstone resists the effects of light, heat, and chemicals. CRYSTAL STRUCTURE️️Regular, repeating internal arrangement of atoms in a material. CHEMICAL FORMULA️️Written description of a material's chemical makeup. TRACE ELEMENTS️️Atoms in a gem that aren't part of its essential chemical composition. AMORPHOUS️️Lacking a regular crystal structure. SPECIES️️A broad gem category based on chemical composition and crystal structure. VARIETY️️A subcategory of species based on color, transparency, or phenomenon. PHENOMENON️️An unusual optical effect displayed by a gem. GROUPS️️A family of gems from several closely related mineral species. NATURAL GEMS️️Gems produced by natural processes, without human help. LAB-GROWN GEM️️A manmade (synthetic) gem with essentially the same chemical composition, crystal structure, and properties as its natural counterpart. FEDERAL TRADE COMMISSION️️A US government agency that issues guidelines for the jewelry trade. SELECTIVE ABSORPTION️️Process by which a material absorbs some components of visible light and returns others. HUE️️The first impression of an object's basic color. TONE️️Degree of darkness or lightness of a color. SATURATION️️A color's strength or intensity. BODYCOLOR️️A gemstone's basic color, determined by its selective absorption of light. COLOR CENTER️️A small defect in the atomic structure of a material that can absorb light and give rise to a color. COLOR ZONING️️Areas of different color in a gem, caused by variations in growth conditions. PLEOCHROISM️️When a gem shows different bodycolors from different directions. WINDOW️️An area of weak saturation in a transparent gemstone's bodycolor that usually results from the way the gem was cut. EXTINCTION️️Dark areas in a faceted transparent colored stone. COLOR RANGE️️The selection of colors in which a gemstone occurs. FINE COLOR️️The color or colors in a gemstone's color range considered by the trade to be the most desirable. DISPERSION️️The separation of white light into spectral colors. FLUORESCENCE️️Emission of visible light by a material when it's stimulated by ultraviolet radiation. TRADE TERMS️️Terms often used in the jewelry industry to describe particular gemstone colors or link gems with specific geographic locations. PLAY-OF-COLOR️️The flashing rainbow colors in op