1- Basic Terms Flashcards
Amorphous
Lacking a regular crystal structure
Chemical composition
Kinds and relative quantities of atoms that make up a material.
Chemical formula
Written description of a material’s chemical makeup.
Colored stone
Any gem material other than diamond.
Crystal structure
Regular, repeating internal arrangement of atoms in a material.
Durability
A gemstone’s ability to withstand wear, heat, and chemicals.
Federal Trade Commission (FTC)
A US Gov’t agency that issues guidelines for the jewelry trade.
Gemology
The study of gems.
Gem species
A broad gem category based on chemical composition and crystal structure.
Gem variety
A subcategory of species, based on color, transparency, or phenomenon.
Group
A family of gems from several closely related mineral species.
Hardness
How well a gemstone resists scratches and abrasion.
Inorganic
Composed of, or arising from, non-living matter.
Luster
The appearance of a material’s surface in reflected light.
Mineral
A natural, inorganic substance with a characteristic chemical composition and usually characteristic structure.
Natural gems
Gems produced by natural processes, without human help.
Organic
Once living, or produced by a living organism (plant or animal.)
Phenomenon
An unusual optical effect displayed by a gem.
Stability
How well a gemstone resists the effects of light, heat, and chemicals.
Lab-grown gem
A manmade (synthetic) gem with essentially the same chemical composition, crystal structure, and properties as its natural counterpart.
Toughness
How well a gemstone resists breaking, chipping, or cracking.
Trace elements
Atoms in a gem that aren’t part of its essential chemical composition.
What traits do all gems share?
Beauty, rarity, and durability.
Why is color the most important factor in a colored stone’s visual appeal?
Because color is the first thing a consumer notices.
What features help classify gems?
Chemical composition, crystal structure, transparency, and phenomenon.
