Datolite



Datolite, a calcium boron silicate hydroxide mineral, was first described by Penfield and Foote (1897) from the Parker Mine, but it is not known from Sterling Hill.
Datolite occurs as fine, colorless, euhedral crystals to several cm in vuggy, recrystallized assemblages. Crystal habits are complex; tabular crystals are known. The fine crystals from Franklin have been studied morphologically by Palache (1910), Ungemach (1911), Gordon (1923b), and Bauer and Berman (1930); these morphological works are summarized by Palache (1935). Additional morphological description was provided by Richards (1989). Datolite is colorless to light pink, with vitreous luster, and no cleavage. Franklin datolite has been little studied in other repects and not at all chemically.
Datolite occurs in the recrystallized areas at Franklin. It occurs as single crystals and as druses; some are dull-lustered and some are bright. It also forms splendid crystals up to 1 cm in size; most are 1-2 mm. Botryoidal crusts of datolite, called botryolite, were found in 1926. Datolite commonly lines vugs in recrystallized assemblages and seams and occurs as druse botryoidal coatings on rhodonite, manganaxinite, and cahnite. The bulk of the extant specimens are composed of massive, medium- to fine-grained, vuggy aggregates of andradite, manganaxinite, mica, prehnite, nasonite, clinohedrite, impure hancockite, and other species, which were found near the Parker Dump in Franklin. Datolite is among the last minerals to form. (Dunn, 1995)


 Location Found: Franklin
     
 
 Year Discovered: 1804
     
 Formula: Ca(HBSiO5)
 Essential Elements: Boron, Calcium, Hydrogen, Oxygen, Silicon
 All Elements in Formula: Boron, Calcium, Hydrogen, Oxygen, Silicon
     
 IMA Status: Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
     
Fluorescent Mineral Properties

 Shortwave UV light: Bright to weak cream
 Mid wave UV light: Weak cream
 Longwave UV light: Weak cream
     
 To find out more about this mineral at minDat's website, follow this link   Datolite

     
 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.367

Frondel, Clifford (1972). The minerals of Franklin and Sterling Hill, a checklist. NY.: John Willey & Sons. p.53


The Picking Table References
 PT Issue and PageDescription / Comment
V. 57, No. 2 - Fall 2016, pg. 16Fluorescent Minerals of Franklin and Sterling Hill, N.J., Part 1, Richard C. Bostwick - Datolite
View IssueV. 45, No. 1 - Spring 2004, pg. 10The 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 - Datolite
View IssueV. 33, No. 2 - Fall 1992, pg. 10The Check List of Franklin-Sterling Hill Fluorescent Minerals - Datolite (Fluorescent Info)
View IssueV. 30, No, 2 - Fall 1989, pg. 15New Habit for Datolite
View IssueV. 16, No. 1 - February 1975, pg. 7Mineral Notes - Datolite (small article)
     
Images

     
Datolite crystals, margarosanite and hancockite with minor roeblingite and clinohedrite from Franklin, NJDatolite crystals, margarosanite and hancockite with minor roeblingite and clinohedrite from Franklin, NJ under shortwave UV Light
Datolite crystals (clear), margarosanite (white) and hancockite (red-brown) with minor roeblingite and clinohedrite from Franklin, NJ. From the collection of, and photo by Robert A. Boymistruk.
Datolite crystals, margarosanite and hancockite with minor roeblingite and clinohedrite from Franklin, NJ under shortwave UV light. The datolite fluoresces light blue, margarosanite sky blue (under the datolite), roeblingite red and the clinohedrite orange, the hancockite is non-fluorescent. From the collection of, and photo by Robert A. Boymistruk.


Botryoidal datolite crystals in a rhodonite vug, Franklin, NJ
Botryoidal datolite crystals (white) in a rhodonite vug from Franklin, NJ. Field of view 7/8". From the collection of, and photo by Robert A. Boymistruk.







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