Definition

Noun: A white or colorless mineral consisting primarily of sodium aluminum fluoride (Na₃AlF₆). It is the principal ore of the element fluorine.

Usage

"Greenland spar" is a technical term used in geology and mineralogy. It refers specifically to the mineral cryolite, historically mined in significant quantities in Greenland.

Examples

• The primary source of cryolite for industry was Greenland spar from Ivittuut.
• Greenland spar is used as a flux to lower the melting point in the electrolytic production of aluminum.
• Under a microscope, the crystal structure of Greenland spar can be clearly observed.

Advanced Usage

• The term is often used in historical contexts regarding mining and early aluminum production.
• In optical mineralogy, its low refractive index, similar to that of water, made it useful for identifying other minerals.

Variants and Related Words

• Cryolite: The more common mineralogical name for Greenland spar.
• Sodium aluminum fluoride: The chemical name for the compound.

Synonyms

• Cryolite
• Ice stone (an archaic name due to its ice-like appearance)

Notes

This is a highly specific term. In modern contexts, the word "cryolite" is more frequently used, while "Greenland spar" emphasizes the mineral's geographical origin and historical commercial importance.

Noun

1. a white mineral consisting of fluorides of aluminum and sodium; a source of fluorine