Hydroxylherderite- Poland, Maine

Hydroxylherderite
Poland, Maine
Dimensions: 2.5 x 1.5 x 0.9 cm

The original vintage label identifies it as “Herderite — Poland, Maine,” but there is an important modern mineralogical distinction worth preserving. Analyses of Maine material historically called herderite have shown that much of it is actually hydroxylherderite, the OH-dominant member of the herderite–hydroxylherderite series. Poland, Maine is specifically documented for hydroxylherderite, including material from the Berry-Havey Quarry.

This specimen features a cluster of translucent colorless to pale champagne crystals with a bright vitreous luster. The crystals are stout and somewhat blocky, with prominent longitudinal growth striations and complex terminations. Smaller crystals crowd between the larger individuals, while scattered tan-to-brown matrix material provides contrast throughout the cluster.

The piece has the classic appearance of an old New England pegmatite specimen and is particularly appealing because it retains its original catalog label, No. 492, identifying the material as Herderite from Poland, Maine. Mindat now cautions that many specimens historically labeled “herderite” are hydroxylherderite.