GYPSUM



Gypsum, a calcium sulfate hydrate mineral, was first reported on one specimen each from Franklin and Sterling Hill by Palache (1928a, 1935). Frondel (1972) reported that it had subsequently been found in abundance.
Local gypsum is largely unstudied. Colorless clear cleavage plates and crystals over 10 cm are known to occur at Sterling Hill, but much massive white material may lie in collections unrecognized. Bostwick (1982) reported a moderate pale blue to white fluorescence in shortwave ultraviolet. Gypsum is most commonly associated with calcite in vein assemblages and locally may be associated with anhydrite or other minerals. In addition to the two specimens mentioned by Palache, gypsum has also been found on the 1500 and 1750 levels at Sterling Hill and as a white powder associated with hancockite, clinohedrite, and andradite from Franklin. It is part of the surficial alteration of charlesite. (Dunn, 1995)


 Location Found: Franklin and Ogdensburg
     
 
     
 Formula: CaSO4 · 2H2O
 Essential Elements: Calcium, Hydrogen, Oxygen, Sulfur
 All Elements in Formula: Calcium, Hydrogen, Oxygen, Sulfur
     
 IMA Status: Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
     
Fluorescent Mineral Properties

 Shortwave UV light: Moderately bright to weak white, pale yellow, and blue
 Mid wave UV light: Moderately bright to weak white, pale yellow, and blue
 Longwave UV light: White, pale yellow, blue
 Additional Information: Phosphoresces moderately bright to weak white, pale yellow, and blue. Weaker fluorescence at longwave
     
 To find out more about this mineral at minDat's website, follow this link   Gypsum

     
 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.633

Frondel, Clifford (1972). The minerals of Franklin and Sterling Hill, a checklist. NY.: John Willey & Sons. p.59


The Picking Table References
 PT Issue and PageDescription / Comment
View IssueV. 57, No. 2 - Fall 2016, pg. 19Fluorescent Minerals of Franklin and Sterling Hill, N.J., Part 1, Richard C. Bostwick - Gypsum
View IssueV. 34, No. 2 - Fall 1993, pg. 14Recent Mineral Finds From The Sterling Mine Ogdensburg, New Jersey - Gypsum, Brochantite
View IssueV. 33, No. 2 - Fall 1992, pg. 10The Check List of Franklin-Sterling Hill Fluorescent Minerals - Gypsum (Fluorescent Info)
View IssueV. 18, No. 2 - September 1977, pg. 13The Fluorescent Minerals of Franklin and Sterling Hill, NJ by Richard C. Bostwick - Gypsum
View IssueV. 15, No. 2 - August 1974, pg. 8Fluorescent Corner - Gypsum/Selenite/Quartz
View IssueV. 7, No. 2 - August 1966, pg. 9The Minerals of Sterling Hill 1962-65 by Frank Z. Edwards - Gypsum
     
Images

     
Gypsum (selenite) and franklinite with minor calcite from the Sterling Hill Mine, NJ.
Gypsum (selenite) clear to white and franklinite with minor calcite from the Sterling Hill Mine, NJ. From the collection of, and photo by JVF.


Gypsum (selenite), franklinite and calcite from the Sterling Hill Mine, NJGypsum (selenite), franklinite and calcite from the Sterling Hill Mine, NJ under longwave UV Light
Gypsum (selenite) clear to white, franklinite and calcite from the Sterling Hill Mine, NJ. 3 3/4" x 1 1/2". From the collection of, and photo by WP.
Gypsum (selenite), franklinite and calcite from the Sterling Hill Mine, NJ under longwave UV light. The gypsum fluoresces white to light blue, calcite deep red, and the franklinite is non-fluorescent. 3 3/4" x 1 1/2". From the collection of, and photo by WP.
Gypsum (selenite), franklinite and calcite from the Sterling Hill Mine, NJ under shortwave UV Light
Gypsum (selenite), franklinite and calcite from the Sterling Hill Mine, NJ under shortwave UV light. The gypsum fluoresces blue, calcite red-orange to orange, and the franklinite is non-fluorescent. 3 3/4" x 1 1/2". From the collection of, and photo by WP.







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