Nasonite is a lead calcium silicate chloride mineral. Most analyses conform to the theoretical composition, but there is some limited substitution of Ca for Pb. Nasonite is the only halogen-bearing lead silicate; the Cl content is relatively constant.
Nasonite was originally described from Franklin by Penfield and Warren (1899). The relation to the apatite group was defined by Frondel and Bauer (1951). Analytical data were provided by Dunn (1985b).
The crystal structure of nasonite was described by Giuseppetti et al. (1971); the space group was confirmed by Loiacono et al. (1982). Nasonite is structurally related to the apatites. The structure has Si2O7 groups, Pb in irregular coordination polyhedra, and calcium atoms surrounded by six oxygen atoms at the vertices of trigonal prisms forming columns along the three-fold axis. However, Bres et al. (1987) noted proof of non-hexagonal symmetry, and more work remains to be done.
Nasonite occurs as massive material, granular aggregates, and small 1-2 mm euhedral crystals. The habit of the crystals, unlike those of ganomalite, is markedly prismatic. The morphology was well described by Palache (1910, 1935) and Frondel and Bauer (1951). Crystals of nasonite vary considerably in their height:width ratio; some are stubby and long steeply tapering prismatic crystals, some arranged like jackstraws, have also been found.
Nasonite is white to colorless, with adamantine to greasy luster, basal and prismatic cleavages, and a density of 5.55 g/cm3. Much nasonite is fluorescent in shortwave ultraviolet, with a pale yellow to white color. It is differentiated by its high luster and mineral associations; barite has better quality cleavages and a lower luster.
In the original occurrence nasonite was associated with euhedral crystals of glaucochroite; in this assemblage it is also associated with cuspidine, pennantite, and barite. The best of these nasonite samples, described by Palache (1910, 1935), is preserved in the Smithsonian Institution.
Nasonite occurs with more species than any of the other lead silicates from the Parker Mine area. Although it occurs with high-temperature minerals, it is found as the last-formed mineral in such assemblages. Additionally, it occurs as a filler in interstices in other silicates. The most commonly associated minerals are barysilite, manganaxinite, willemite, and andradite. Less common ones are barite, glaucochroite, ganomalite, datolite, cuspidine, prehnite, johannsenite, clinohedrite, margarosanite, and hardystonite. Nasonite occurs as intimate mixtures, especially with datolite, and also with prehnite and other minerals. (Dunn, 1995)

 Location Found: Franklin (Type Locality)
 Year Discovered: 1899
 Formula: Pb6Ca4(Si2O7)3Cl2
 Essential Elements: Calcium, Chlorine, Lead, Oxygen, Silicon
 All Elements in Formula: Calcium, Chlorine, Lead, Oxygen, Silicon
 IMA Status: Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Fluorescent Mineral Properties

 Shortwave UV light: Weak pale yellow
 Mid wave UV light: Weak pale yellow
 To find out more about this mineral at minDat's website, follow this link   Nasonite

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.418

Frondel, Clifford (1972). The minerals of Franklin and Sterling Hill, a checklist. NY.: John Willey & Sons. p.69

The Picking Table References
 PT Issue and PageDescription / Comment
View IssueV. 58, No. 1 - Spring 2017, pg. 14Fluorescent Minerals of Franklin and Sterling Hill, N.J., Part 2, Richard C. Bostwick - Nasonite
View IssueV. 45, No. 1 - Spring 2004, pg. 13The Art of Fluorescent Mineral Photography, With Special Attention to the Minerals of Franklin and Sterling Hill Photographing the More Popular Franklin and Sterling Hill Fluorescent Minerals - Nasonite
View IssueV. 33, No. 2 - Fall 1992, pg. 11The Check List of Franklin-Sterling Hill Fluorescent Minerals - Nasonite (Fluorescent Info)
View IssueV. 33, No. 1 - Spring 1992, pg. 22The Lead Silicate Minerals of Franklin, New Jersey: an SEM Survey, Herb Yeates, Nasonite
View IssueV. 30, No. 1 - Spring 1989, pg. 17Research Reports, Nasonite
View IssueV. 28, No. 1 - Spring 1987, pg. 25Mineral Notes Research Reports, The Margarosanite Assemblage, Nasonite
View IssueV. 13, No. 1 - February 1972, pg. 12Franklin Mineral Notes - Nasonite

Nasonite, prehnite, clinohedrite, willemite, xonotlite, hancockite, hendricksite, andradite garnet, frankliniteNasonite, prehnite, clinohedrite, willemite, xonotlite, hancockite, hendricksite, andradite garnet, franklinite under shortwave UV Light
Nasonite, prehnite, clinohedrite, willemite, xonotlite (fluorescent), hancockite, hendricksite mica, andradite garnet, and franklinite (non-fluorescent) from Franklin, NJ. Photo by JVF.
Nasonite, prehnite, clinohedrite, willemite, xonotlite, hancockite, hendricksite mica, andradite garnet, and franklinite from Franklin, NJ under Shortwave UV light. The nasonite fluoresces dull white (gray), prehnite peach pink, clinohedrite orange, willemite green, and some xonotlite deep blue. Photo by JVF.

All content including, but not limited to, mineral images, maps, graphics, and text on the Franklin-Ogdensburg Mineralogical Society, Inc. (FOMS) website is licensed under a
Creative Commons Attribution-NonCommercial 4.0 International License.
Creative Commons License