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Semiarid landscape around the Harding Mine / Iceberg claim

Source : S. Schmidt at

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Spodumene - Spodumen - Spodumene - Espodumena

 Calcite - Calcit - Calcite - Calcita

America : USA : New Mexico : Giant spodumene and equally giant calcite crystals in the Harding mine area

Coordinates : 36°11'N , 105°47'W : Harding Mine & Iceberg Claim, Dixon, Taos Co., New Mexico, USA


The Harding mine in New Mexico was mined from about 1900 intermittenly until 1958 as source for various metals such as beryllium, lithium and tantalum. It is an interesting counterpiece to the Etta mine in South Dakotah. As in the famous Etta mine we have giant - though somewhat smaller - spodumene crystals in a quartz - feldspar pegmatite, which were and which still are (!) beautifully exposed in a long mine wall. Rather than forming individual logs the white coloured spodumene crystals grow in fan like shapes from the lower part of the pegmatite, sometimes forming large stellate aggregates.

Strange enough a completely different occurence of giant crystals can be found only some 150 m away from the Harding pegmatite. Here a rocky outcrop called "Iceberg Claim" was explored and mined in the 1930s for optical calcite / icelandic spar. The individual anhedral - that is : non idiomorphic - calcite crystals discovered and mined reached a dimension of several meter and were in large parts of remarkable clarity. V.C. KELLEY (1940) wrote an report about this icelandic spar crystals, which can be accessed here.

After abandoment of all mining activities 1978 the whole property was donated to the University of New Mexico, which still owns it today and carry out geological research in the Harding area. The mine and the surrounding is therefore a protected geological heritage site, which is still open to all geologically interested parties.


Other notable & famous spodumene occurences :

- Another locality with giant spodumene crystals is the nearby Tin Mountain quarry, where a 10 m large spodumene crystal was discovered.

- A further well known north american spodumene locality is the Harding mine in New Mexico, where a multitude of up to 5 m long crisscrossing spodumene crystals in the pit walls are still acessible today. For more information click here.

- The largest known european spodumene deposit with rich reserves and many rare minerals is the well explored, but never seriously mined Weinebene pegmatite at the Koralpe, Carinthia, Austria

- Gemmy spodumene of the pink variety known as kunzite can reach up to 1 m crystal size and is reported both from Brasilia (photo as well as from the Nuristan region, Pakistan

Other notable & famous calcite occurences :

- More information about giant Iceland spar occurences can be found here (Helgustadir/Iceland), here (Hejiawan, China) and here (Garibaldi mine, Australia)

- Another remarkable Iceland spar deposit with crystals up to 0,7 x 0,5 cm occur in basalt from Nizhnyaya, Krasnoyarsk kray Siberia, GUS.

- Sharp yellow scalenohedral crystals up to 1 m occur with galena and sphalerite in the famous Tri State District, Oklahoma / Missouri / Kansas, USA.

- For more information about calcite pseudomorphs after giant ikaite crystals and crystal aggregates please look here and here.

- Large to giant crystals of calcite up to 1 x 1 m size from metamorphic marbles have been reported from Sterlingbush, New York, USA.

- As calcite is one of the most common minerals, there are certainly other remarkable giant crystal occurences not listed here.

Miners amongst giant spodumene crystals in the Harding mine

Photo source : Harding mine website

Mining of spodumene ore from single giant crystals in the 1940s

Photo source : Harding mine website

Miner with giant spodumene crystals

Photo source : Harding mine website

Harding Mine Essentials :

Mineralogy :

Spodumene and Iceland Spar Calcite as giant crystals with feldspar, mica and other minerals as pegmatite matrix.

Crystal Size :

The slender spodumene laths reach several m in lenght, while anhedral icelandic spar (calcite) crystals of up to 40 tons (no dimensions given) are recorded.

Geology & Origin :

Pegmatite (spodumene) and probably hydrothermal (calcite)

Current status :

The property is owned and protected by the University of New Mexico, which is conducting geological research and fieldtrips for visitors in the area.

Remarks :

A giant crystal locality as it should be. Acessible to the science and the public alike, though protected by law and the scientific community.
Resources and relevant weblinks :

The Harding mine has a good, though somewhat incomplete website, which gives a lot of information about the present site and its history.
It can be reached here.

Additionaly there is an interesting report by KELLEY,V.C. (1940) :
Iceland Spar in New Mexico; in : Amer. Min, Vol. 25, pages 357 - 367 about the giant anhedral calcite crystals found nearby, which is
accessible in our Reading Room..


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