What does amblygonite mean?
Amblygonite is a rare phosphate mineral composed of lithium, aluminium, phosphorus, oxygen, fluorine, and hydroxyl, with the chemical formula LiAl(PO₄)F(OH). It occurs chiefly in granite pegmatites — coarse-grained igneous rocks — where it forms translucent white, cream, yellow, or pink masses and crystals characterized by good cleavage, a waxy to vitreous luster, and relatively blunt-angled crystal faces that inspired its Greek-derived name. Because of its significant lithium content, amblygonite has served historically as a minor ore of lithium, though richer sources such as spodumene have largely supplanted it commercially. Transparent, gem-quality specimens are uncommon, making faceted amblygonite primarily a collector's curiosity rather than a widely traded gemstone. The word belongs to the specialized vocabulary of mineralogy and geology, appearing mainly in field guides, scientific papers, and dealer catalogues. For collectors, its appeal lies in its rarity, gentle pastel hues, and its place within the fascinating mineralogy of lithium-rich pegmatites.
nounA rare lithium aluminium phosphate mineral, LiAl(PO₄)F(OH), typically found in granite pegmatites and valued as a source of lithium and occasionally as a collector's gemstone.
- The rare lithium aluminium phosphate mineral LiAl(PO₄)F(OH) found in granite pegmatites, used as a lithium ore and occasionally cut as a gemstone.
"The prospectors identified amblygonite in the pegmatite vein by its distinctive cleavage and waxy luster."
"Museum curators prized the translucent yellow amblygonite crystal, one of the finest specimens ever recovered from Minas Gerais."
"Because of its high lithium content, amblygonite was once mined alongside lepidolite as a commercial ore."
As a countable noun naming a mineral species, 'amblygonites' pluralizes normally, though in practice the singular is far more common since discussions usually concern the species as a whole or a single specimen.
"The museum drawer held amblygonites from three continents, each a different shade of cream and yellow."
Named for its 'blunt angles' — the mineral literally got its name because its crystals refuse to form sharp points.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of amblygonite
The name amblygonite derives from the Greek words 'amblys,' meaning blunt, and 'gōnia,' meaning angle, referring to the obtuse angles between the mineral's cleavage planes. The German mineralogist August Breithaupt coined the name in the nineteenth century when he described the species. The same Greek roots appear elsewhere in English: 'amblys' underlies medical terms such as amblyopia, while 'gōnia' gives us polygon, diagonal, and trigonometry.
How amblygonite is actually used
A technical term used almost exclusively in mineralogy, geology, and gemology; it rarely appears in general conversation or literature. Among gem collectors, gem-quality transparent material is scarce and commands interest as a collector's stone rather than a mainstream jewel.
Easily confused with amblygonite
Spodumene is a lithium pyroxene silicate, whereas amblygonite is a lithium aluminium phosphate; the two often occur together in pegmatites but differ in crystal structure, hardness, and chemical composition.
Petalite is a lithium aluminium silicate with perfect basal cleavage, while amblygonite is a lithium phosphate with good cleavage in two directions and a higher specific gravity.