Kentrolite, a lead manganese silicate mineral, was reported by Palache (1935) on the basis of morphological examination only. No specimens were preserved or found for over 50 years. It was found again by [Dunn] in 1986, associated with groutite, cahnite, hetaerolite, and calcite in a brown andradite matrix; this is the more common of the two assemblages for Franklin groutite (Dunn, 1987). It was verified using X-ray powder-diffraction methods, and a semi-quantitative analysis showed only Mn, Pb, and Si as constituents.
Another assemblage, consisting of specular crystals of kentrolite associated with barysilite and willemite from Franklin, was described and illustrated by Yeates (1991), who found it to have end-member composition. Later in 1991 another possibly different assemblage of deep-red crystals of kentrolite associated with manganaxinite, cahnite, and datolite was noted by Cianciulli (1991b). Because Palache (1935) did not mention these distinct assemblages, a different kentrolite-bearing assemblage may have been known to him. (Dunn, 1995)

 Location Found: Franklin
 Year Discovered: 1880
 Formula: Pb2Mn23+(Si2O7)O2
 Essential Elements: Lead, Manganese, Oxygen, Silicon
 All Elements in Formula: Lead, Manganese, Oxygen, Silicon
 IMA Status: Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
 To find out more about this mineral at minDat's website, follow this link   Kentrolite

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.415

The Picking Table References
 PT Issue and PageDescription / Comment
View IssueV. 33, No. 1 - Spring 1992, pg. 21The Lead Silicate Minerals of Franklin, New Jersey: an SEM Survey, Herb Yeates, Kentrolite
View IssueV. 32, No. 2 - Fall 1991, pg. 15More on The Mineral Kentrolite From Franklin, New Jersey
View IssueV. 28, No. 2 - Fall 1987, pg. 4Kentrolite, Groutite, Manganite, and Hausmannite From Franklin, New Jersey: Some Observations, Dr. Pete J. Dunn, Kentrolite
View IssueV. 28, No. 1 - Spring 1987, pg. 3From the Laboratory, Dr. Pete J. Dunn, John L. Baum, Kentrolite
View IssueV. 9, No. 1 - February 1968, pg. 8Mineralogical Data - Kentrolite
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