Natural

      A naturally occurring gemstone that has only undergone the standard process of cutting and polishing.

   Treated

        Gemstones that have undergone changes in color, clarity, and/or durability. Processes described as treatments typically                go beyond what is considered standard enhancement. Examples: diffused sapphire, Mystic topaz (CVD), irradiated blue                  diamond.

Artificial/Man made

     The term artificial is a catch-all for any man made or lab-created gem. Artificial gems that have the same chemical,optical,               and physical properties as their natural counterparts are more accurately described as synthetic. Any gemstone not  of                 natural origin is considered artificial in gemological terms.

Synthetic

     The term synthetic is used to describe a lab-created gemstone that has a natural counterpart. Synthetic gemstone have               the same chemical, optical, and physical properties as those occurring in nature. Examples: synthetic sapphire, synthetic               alexandrite.

Stimulant

      The term stimulant is synonymous with substitute or imitation. A stimulant only mimics the appearance of another more               expensive gemstone. A stimulant usually indicates a man-made material, but may be natural. Examples: red glass (ruby                 stimulant), white YAG (diamond stimulant).

  Lab Created

      The term lab created is used to describe any material made by man. Lab-created gems with no natural counterparts fall               into the category of artificial, and are used as stimulants. Lab-created gems that duplicate the same chemical, optical,                   and physical properties as their natural counterparts are more accurately described as synthetic.

Imitation 

     See stimulant. The term imitation is used to describe any material that mimics the appearance of a natural more      

     expensive gemstone. Imitations may be man-made or natural. Examples: red glass (imitation ruby), white YAG (imitation              diamond), red garnet (imitation ruby)

Hybrid

     A stone with natural and artificial components, where the two cannot be separated. New category created by a new                        generation of treatments that add materials to a natural base material. In most cases, undesirable elements of natural                   material are removed and replaced by added artificial gem material; lead glass, polymers or synthetic material.                       

Enhancement

     A process that improves a natural gemstone's appearance or durability by an accepted industry practice. Examples:                      heated citrine, bleached Akoya pearls

Color Enhanced

      Color has been improved by various processes or agents.

Clarity Enhanced

     Clarity has been improved with colorless glass, oil, plastic, resin or some similar substance.

   Hardness       

      Hardness is the ability to resist scratching.

Toughness

      Toughness is the ability to resist breakage (deformation in the presence of external forces).

Stability

      Stability is the ability to remain unchanged in the presence of heat, light, and/or chemicals.

Durability

      Durability is defined as a combination of hardness, toughness, and stability.

Standard Pearl Processing

      Routine cleaning and bleaching of cultured pearls.