A Geoscience Digital Image Library

DescriptionAmblygonite, (Li,Na)AlPO4(F,OH), is a relatively common phosphate mineral. It is found in lithium- and phosphate-rich pegmatites as a primary mineral. It may be a major rock former but is often overlooked because it is hard to distinguish from other minerals such as quartz and albite. It can be differentiated with a flame test for lithium, density and by its unusual cleavage. Amblygonite has no less than four different directions of cleavage at different angles from one another and with different qualities of cleavage. Amblygonite, montebrasite, natramblygonite, natromontebrasite, and a mineral named tavorite all belong to a group of minerals called the Amblygonite Group. It's name comes from the Greek amblys meaning “blunt” and goni meaning “angle”, in reference to its distinctive cleavage.
LocationUSA ▹ South Dakota. Near Hill City. Black Hills.
PhotographerShannon Heinle. 2001-06-27.
CollectionUniversity of North Dakota Mineralogy Collection #1019.
Key wordsamblygonite, phosphate, pegmatites
Tech details594 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number925