Definition of variety
In general mineralogical use, a variety is a mineral (or other substance) showing differences in colour, habit, or other external physical characteristics, or minor variations in composition from the material considered typical of the species.
Classic examples of varieties include:
Ruby - a variety of corundum showing distinctive red colour.
Amethyst - a variety of quartz showing a distinctive purple colour.
Tarnowizite - a variety of aragonite containing appreciable lead (Pb).
In mindat.org usage, the term variety has been expanded to include names that have specific meaning beyond the standard mineral name, and when the two names are not 100% interchangeable (if they are, they are known as synonyms.) This includes variety names distinct only by form, habit or even by geographical location of origin. Many names are colloquial and/or historical and many of these names should be discouraged from general use.
An example of this usage within mindat.org:
Herkimer diamond - this variety of quartz, from upper New York state, USA, shows the classic form and properties of quartz. It is not a synonym because although all 'herkimer diamond' specimens are quartz, not all quartz can be called 'herkimer diamond'.
Classic examples of varieties include:
Ruby - a variety of corundum showing distinctive red colour.
Amethyst - a variety of quartz showing a distinctive purple colour.
Tarnowizite - a variety of aragonite containing appreciable lead (Pb).
In mindat.org usage, the term variety has been expanded to include names that have specific meaning beyond the standard mineral name, and when the two names are not 100% interchangeable (if they are, they are known as synonyms.) This includes variety names distinct only by form, habit or even by geographical location of origin. Many names are colloquial and/or historical and many of these names should be discouraged from general use.
An example of this usage within mindat.org:
Herkimer diamond - this variety of quartz, from upper New York state, USA, shows the classic form and properties of quartz. It is not a synonym because although all 'herkimer diamond' specimens are quartz, not all quartz can be called 'herkimer diamond'.
