American alexandrite
La Madera Mountain is a mine in Rio Arriba County, New Mexico, which is reported to produce occasional small chrysoberyl crystals with weak color change.
Locality details
Country	United States of America	
Region	New Mexico	
Province	Petaca District	
Locality	La Madera Mtn.	
Latitude	35.2228	
Longitude	-106.3700	
Altitude	6938	
Time zone	UTC-7(-6DT)	
Locality maps
Map	Satellite	
		
The best known pegmatite in New Mexico is the Harding pegmatite dike, well exposed in mine workings east of Dixon, Taos County. Once owned by Dr. Arthur Montgomery and subsequently donated to the University of New Mexico, it was mined over the years for lithium (lepidolite and spodumene), tantalum (microlite and columbite-tantalite), and beryl, (some of which is pink beryl rich in alkali metals and H2O). Other distinctive minerals found at the Harding mine include rose muscovite, fluorapatite, eucryptite and many more. Montgomery (1951) gave an interesting and classic account of the beryl mining, in which three men and a mule produced several hundred tons of hand-sorted beryl per year.
In recent years a number of other pegmatites occurring locally in northern New Mexico have produced minerals, often in well-crystallized form, including beryl, chrysoberyl, gahnite, titanite, epidote, margarite, and schorl, thanks to the diligent efforts of astute and observant collectors such as Ramon DeMark, Jesse Kline, and others.