EDENITE

Edenite, a sodium calcium magnesium silicate hydroxide mineral of the amphibole group, was reported by Palache (1935) from the Franklin marble on the basis of the compositional similarity of local material and the type material from New York. It has not been studied since. The analysis by Gonyer given by Palache is calculated as edenitic hornblende using the conventions of Leake (1978). Many crystals of green color from the various marble quarries in the area, and known to local collectors as edenite, were examined and found to be largely pargasite; some were edenitic magnesiohornblende or pargasitic hornblende. Much of the material described by Palache as edenite is likely pargasite, which is abundant here.
Edenite has been verified by [Dunn] from Sterling Hill as 25 mm black euhedral crystals. Additional validated edenites are held in private collections, and one is in the Franklin Mineral Museum (FMM-Cook #168). (Dunn, 1995)

Location Found:

Franklin and Ogdensburg

Mineral Note:

Possibly fluoro-edenite; further analyses needed to establish F:OH ratios.

Year Discovered:

1839

Formula:

{Na}{Ca₂}{Mg₅}(AlSi₇O₂₂)(OH)₂

Essential Elements:

Aluminum, Calcium, Hydrogen, Magnesium, Oxygen, Silicon, Sodium

All Elements in Formula:

Aluminum, Calcium, Hydrogen, Magnesium, Oxygen, Silicon, Sodium

IMA Status:

Approved

To find out more about this mineral at minDat's website, follow this link Edenite

References:

Dunn, Pete J. (1995). Franklin and Sterling Hill New Jersey: the world's most magnificent mineral deposits. Franklin, NJ.: The Franklin-Ogdensburg Mineralogical Society. p.454

Frondel, Clifford (1972). The minerals of Franklin and Sterling Hill, a checklist. NY.: John Willey & Sons. p.54

The Picking Table References

	PT Issue and Page	Description / Comment
View Issue	V. 18, No. 1 - March 1977, pg. 24	The Fluorescent Minerals of Franklin and Sterling Hill, NJ by Richard C. Bostwick - Edenite
View Issue	V. 15, No. 2 - August 1974, pg. 14	Other Mineral Notes - Edenite

Images


Edenite crystals (dark gray-green) from Franklin, NJ. Field of view 1 1/8" (29 mm). From the collection of Mark Dahlman, photo by WP.