Hodgkinsonite Value, Price, and Jewelry Information

Hodgkinsonite: Franklin, New Jersey. (0.35). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Hodgkinsonite

Hodgkinsonite is one of the rarest of all collector gems. Cut stones are bright and richly colored, but the crystals were never abundant and still fewer had transparent areas. Fewer than 10 cut stones may exist.

Hodgkinsonite Information

Data Value
Name Hodgkinsonite
Colors Bright pink to reddish brown, purplish pink.
Hardness 4.5 - 5
Fracture Conchoidal
Cleavage Perfect 1 direction
Stone Sizes Cut gems are very small, less than 2 carats. This is an exceedingly rare material, available from only one locality and only from older specimens. Private Collection: 0.89,
Formula MnZn2SiO5· H20
Crystallography Monoclinic. Crystals pyramidal or prismatic; massive; granular.
Refractive Index 1.720-1.746
Birefringence 0.026
Luminescence Dull red in LW.
Luminescence Present Yes
Luminescence Type Fluorescent, UV-Long
Absorption Spectrum Not diagnostic.
Pleochroism Distinct: lavender/colorless/lavender.
Optics a = 1.720; β = 1.741; γ = 1.746. Biaxial (- ), 2V= 52°.
Optic Sign Biaxial -
Luster Vitreous.
Specific Gravity 3.91-3.99
Transparency Transparent (rare) to translucent.

Opticsa = 1.720; , β= 1.741; γ= 1.746.

Biaxial (- ), 2V= 52°.

Occurrence: in metamorphosed limestone at Franklin, New Jersey with various other Zn and Mn minerals. Individual crystals reached ¾ inch in diameter, in veins up to several inches thick. The material was mined out years ago.

Comments: Hodgkinsonite is one of the rarest of all collector gems. Cut stones are bright and richly colored, but the crystals were never abundant and still fewer had transparent areas. Fewer than 10 cut stones may exist.

Name: After H. H. Hodgkinson of Franklin, New Jersey, who discovered the mineral.

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