Locality: Draper Hill, Chesterfield, NH
Specimen Size: 10 cm specimen with prismatic gray-white sillimanite crystals to 1.7 cm
Field Collected: Tom Mortimer
Catalog No.: 831
Notes:
Locality: Ledge below Palermo #1 Mine, N. Groton, NH
Specimen Size: 9 cm specimen with cream-colored sillimanite crystals to 4.5 cm in biotite schist.
Field Collected: Tom Mortimer
Catalog No.: 1460
Notes:
Locality: Ledge below Palermo #1 Mine, N. Groton, NH
Specimen Size: Zoom view of specimen 1460 showing splintery structure of sillimanite crystal section. Field of view 1 cm.
Field Collected: Tom Mortimer
Catalog No.: 1460
Notes:
Locality: Mine road to Valencia Mine, N. Groton, NH
Specimen Size: 3.5 cm specimen with white sillimanite crystal sections to 1.3 cm in biotite schist.
Field Collected: Tom Mortimer
Catalog No.: 1598
Notes:
Locality: Draper Hill, Chesterfield, NH
Specimen Size: 6 cm specimen with prismatic gray-white sillimanite crystals to 1.4 cm
Field Collected: Walter Caulkin
Catalog No.: 806
Notes: This is the specimen I acquired from Walter Caulkin at the June 1990 Gilsum Rock Swap. A short time later, Walter guided me to the Chesterfield, NH source locality.
Locality: West side of Piper Mtn., Gilford, NH
Specimen Size: 5 cm specimen with sillimanite crystals in biotite-garnet schist
Field Collected: Kevin Mortimer - Sept, 2011
Catalog No.: 1800
Notes: Likely from Rangely formation. Hardness tested slightly less than 6.
Locality: Panned from stream on west side of Piper Mtn., Gilford, NH
Specimen Size: 9 mm sillimanite crystal
Field Collected: Tom Mortimer - Sept, 2011
Catalog No.: u1228
Notes: From Rangely formation. Hardness tested slightly less than 6.
Locality: Rt 11 road cut, near Minge Cove, Alton, NH
Specimen Size: 3 cm partial sillimanite crystal, (upper middle) in 5.5 cm specimen. Matrix is quartz.
Field Collected: Tom Mortimer (2011)
Catalog No.: 1817
Notes: An aluminum silicate mineral was indicated by EDS analysis. Minerals with this chemistry include sillimanite, kyanite, and andalusite. The hardness tested as 7 to 7.5. This, combined with observed silky-fibrous texture in some areas suggests the species is sillimanite. However other zones within the two specimens collected are more bladed and blueish, suggesting kyanite. Deer, Howie & Zussman state in An Introduction to Rock Forming Minerals that "The polymorphic transition of kyanite to sillimanite appears to be sluggish and local persistance of kyanite in the sillimanite zone of metamorphism is not uncommon." The appearance of this crystal suggests that it was undergoing such a polymorphic transition.
Locality: Rt 11 road cut, near Minge Cove, Alton, NH
Specimen Size: 8 cm specimen with with kyanite-sillimanite crystal zoning. Matrix is biotite gneiss.
Field Collected: Tom Mortimer (2011)
Catalog No.: 1818
Notes: Zoom view of bottom side shows gray, un-altered sillimanite, top left, blueish kyanite to right.
These Alton specimens are the only examples the author has seen of New Hampshire sillimanite-kyanite zoned crystals.
Locality: Everet Dam, Weare, NH
Specimen Size: 6 cm specimen
Field Collected: Tom Mortimer
Catalog No.: 1848
Notes: Sillimanite is common in the ledge and rip-rap of the Everet Dam. Collectors unfamiliar with this species should look for lustrous, splintery, gray-white blades embedded in the schist matrix. These blades are difficult to spot in this photo. The sillimanite is the prominent gray-white mineral throughout the specimen.
A Fourier Transform InfraRed analysis (FTIR Analysis) was done on a sample from this specimen and a sample from the #831 Draper Hill specimen, above. The analysist stated this was a very good correlation.