WOLLASTONITE

Wollastonite is a calcium silicate mineral of the pyroxenoid group. Local material has been little studied. Mason (1975) reported a wollastonite with up to 8.09 % MnO with exsolved bustamite; zinc was absent. Baum (1972) reported MnO contents of 6.9 and 2.6 wt. %, respectively, for the initial Franklin occurrence and the two subsequent ones, as noted below.
Wollastonite is known from both Franklin and from Sterling Hill, where it occurs abundantly. Franklin wollastonite was described in coexistence with bustamite by Mason (1975), and the relation was further discussed by Ohashi and Finger (1978). Many data on the occurrence of local wollastonites were given by Baum (1972).
Wollastonite from Franklin and Sterling Hill occurs as white rock-locked idiomorphic crystals, varying in size up to 7 cm; the luster is vitreous, and the cleavages are perfect, resulting in splintery breakage. Local material has not been examined optically. The fluorescence in ultraviolet varies in both hue and intensity, perhaps due to Mn content. In general, the fluorescence is strong in shortwave and weak in longwave. The best Franklin specimens fluoresce with a vivid orange color and occur in assemblages (calcite, willemite, hardystonite) which provide spectacular fluorescent specimens. Sterling Hill wollastonite occurs in idiomorphic crystals, and thus also provides very esthetic fluorescent specimens; the fluorescent color varies substantially, from orange to light yellow. Wollastonite is sometimes visually confused with pectolite or prehnite, both of which can be white and fibrous.
Generally, most wollastonite from Franklin and Sterling Hill is associated with calcite, unanalyzed garnet, and a clinopyroxene, probably diopside. The best statements on the occurrences of Franklin and Sterling Hill wollastonite are those of Baum (1972).
At Franklin, wollastonite was first found in 1944 in grains up to 7 cm, 70 feet below the 600 level, in disseminated lean ore 12 feet from a pegmatite on the footwall. Additional occurrences were on the 900 level near the Palmer Shaft pillar and on the 1050 level, both associated with barite and tremolite. Some Franklin specimens are very rich, with wollastonite forming between hardystonite and calcite, such as occurred in pillar 290 on the 1000 level. Another notable Franklin occurrence is of mostly fine-grained or fibrous wollastonite, associated with microcline, grossular, vesuvianite, allanite, margarosanite, and minehillite.
At Sterling Hill, wollastonite was first found in a drill-core and subsequently on the 900 level, 70 feet west of the west limb of the orebody. Baum (1972) noted that this material is similar to that from Willsboro, Essex County, New York, and that several tons of the New York material had been brought to the Franklin Mill for experimental purposes; thus, local collections may be tainted in part. Much Sterling Hill wollastonite has been found between the 340 and 1600 levels, near the footwall of the east limb; these finds provided the best fluorescent specimens, and substantial quantities have been preserved. Johnson (1990) reported nearly pure end-member wollastonite, associated with titanite from beneath the east limb, on the 1400 level, at the 1060 crosscut. Additionally, wollastonite has been found in other scattered occurrences. (Dunn, 1995)

Location Found:

Franklin and Ogdensburg

Formula:

CaSiO₃

Essential Elements:

Calcium, Oxygen, Silicon

All Elements in Formula:

Calcium, Oxygen, Silicon

IMA Status:

Valid - first described prior to 1959 (pre-IMA) - "Grandfathered" 1962

Fluorescent Mineral Properties

Shortwave UV light:

Bright to moderately bright orange, yellow-orange, orange-yellow, and yellow, weak pink, lavender

Mid wave UV light:

Moderately bright orange, yellow-orange, orange-yellow, and yellow, weak pink, lavender

Longwave UV light:

Moderately bright orange, yellow-orange, orange-yellow, and yellow, weak pink, lavender

Additional Information:

Phosphorescence is often redder than fluorescence

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

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.449

Frondel, Clifford (1972). The minerals of Franklin and Sterling Hill, a checklist. NY.: John Willey & Sons. p.84

The Picking Table References

	PT Issue and Page	Description / Comment
	V. 64, No. 2 - Fall 2023, pg. 8	Shortwave-Fluorescing Bustamite From Franklin, New Jersey, in a Wollastonite Assemblage James Van Fleet
View Issue	V. 58, No. 1 - Spring 2017, pg. 23	Fluorescent Minerals of Franklin and Sterling Hill, N.J., Part 2, Richard C. Bostwick - Wollastonite
View Issue	V. 54, No. 1 - Spring 2013, pg. 23	Ore-Contact Wollastonite, A Previously Undocumented Occurrence at Franklin, New Jersey (Has table of minerals associated with occurrence type)
View Issue	V. 46, Spring/Fall 2005, pg. 21	Upon Furthur Reflection...A Correction to "Wollastonite From Franklin, New Jersey" Richard C. Bostwick
View Issue	V. 45, No. 2 - Fall 2004, pg. 9	Wollastonite From Franklin, New Jersey by Richard C. Bostwick (long article, first, second, third, original and dump find with pictures)
View Issue	V. 45, No. 1 - Spring 2004, pg. 14	The 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 - Wollastonite
View Issue	V. 35, No. 1 - Spring 1994, pg. 16	Geology and Mineralogy of a Veinlet Assemblage Associated With Wollastonite-Bearing Rocks, Sterling Mine, Ogdensburg, New Jersey, Robert E. Jenkins II
View Issue	V. 34, No. 2 - Fall 1993, pg. 14	Recent Mineral Finds From The Sterling Mine Ogdensburg, New Jersey - Wollastonite
View Issue	V. 33, No. 2 - Fall 1992, pg. 11	The Check List of Franklin-Sterling Hill Fluorescent Minerals - Wollastonite (Fluorescent Info)
View Issue	V. 19, No. 2 - September 1978, pg. 6	Recent Mineral Occurrences at Sterling Hill by Stephen Sanford - Wollastonite (small article)
View Issue	V. 18, No. 2 - September 1977, pg. 21	The Fluorescent Minerals of Franklin and Sterling Hill, NJ by Richard C. Bostwick - Wollastonite
View Issue	V. 18, No. 1 - March 1977, pg. 6	Recent Mineral Occurances at Sterling Hill by Stephen Sanford - Wollastonite
View Issue	V. 17, No. 1 - March 1976, pg. 5	Sterling Hill Minerals - Wollastonite
View Issue	V. 13, No. 2 - August 1972, pg. 13	The Fluorescent Minerals of Franklin/Ogdensburg Area by Frank Z. Edwards - Wollastonite (Fluorescent Info)
View Issue	V. 13, No. 1 - February 1972, pg. 4	Franklin Mineral Notes - Wollastonite by John L. Baum
View Issue	V. 7, No. 2 - August 1966, pg. 14	The Minerals of Sterling Hill 1962-65 by Frank Z. Edwards - Wollastonite (small article)

Images


Wollastonite in calcite, with pyrite, and grains and masses of diopside from Sterling Hill Mine. Photo by JVF		Wollastonite in calcite, with pyrite, and grains and masses of diopside from Sterling Hill Mine under shortwave UV light. The wollastonite fluoresces yellow. Photo by JVF


Wollastonite "third find", bustamite (variety ferrobustamite) in calcite from Franklin, NJ. From the collection of, and photo by JVF.		Wollastonite "third find", bustamite (variety ferrobustamite) in calcite from Franklin, NJ under shortwave UV light. The wollastonite fluoresces orange and the calcite dull red-orange. From the collection of, and photo by JVF.


Wollastonite "second find", calcite, willemite, hardystonite, minor garnet, from Franklin, NJ. From the collection of, and photo by Robert A. Boymistruk.		Wollastonite "second find", calcite, willemite, hardystonite, minor garnet, from Franklin, NJ under shortwave UV light. The wollastonite fluoresces yellow-orange, calcite orange-red, willemite green, and the hardystonite blue, the garnet is non-fluorescent. From the collection of, and photo by Robert A. Boymistruk.


Wollastonite "fibrous" and margarosanite, from Franklin, NJ. 2" x 1 1/4". Photo by WP.		Wollastonite "fibrous" and margarosanite, from Franklin, NJ under shortwave UV light. The wollastonite fluoresces orange-yellow and the margarosanite blue. 2" x 1 1/4". Photo by WP.


Wollastonite "green-eyed" and calcite, from Sterling Hill Mine, Ogdensburg, NJ. 6" x 2 3/4". From the collection of Gerry McLoughlin, photo by WP.		Wollastonite "green-eyed" and calcite, from Sterling Hill Mine, Ogdensburg, NJ under shortwave UV light. The wollastonite fluoresces orange-yellow, yellow-orange with green tint and the calcite very weak red. 6" x 2 3/4". From the collection of Gerry McLoughlin, photo by WP.