Acuminite: a colorless, sharply pointed mineral from Ivigtut

Physical characteristics

• Color and clarity: typically colorless and transparent to translucent, which can make faces and terminations easy to examine.
• Crystal habit: crystals tend to be acicular or sharply terminated, giving the species its name; they occur as isolated crystals or small groups rather than massive aggregates. See images of the crystal form at crystal photo.
• Luster and feel: terminations often display a glassy sheen; specimens are usually fragile and can chip at sharp points.
• Hardness: relatively soft in hand specimen — it can be scratched by a copper copper penny, which is a practical field indicator of low hardness.

Occurrence and history

Acuminite is most notably reported from the Ivigtut area in southwestern Greenland, famous for its cryolite mining history. It often appears in veins and pockets associated with cryolite-bearing assemblages and other late-stage minerals in that deposit. The association with the Ivigtut cryolite deposit is discussed in locality summaries such as Ivigtut cryolite and regional geology notes at Greenland mineral records. Historical treatment of the site and its deposits can be found in regional deposit surveys (see deposit record).

Identification, uses and significance

Identification relies on habit, color, and simple physical tests rather than on widespread industrial application. Acuminite is not known for commercial use; its value lies primarily in academic study and private collecting. Typical handling recommendations stress careful storage to avoid breaking pointy crystals and to preserve diagnostic terminations.

Similar minerals and notable facts

Because of its color and habit, acuminite can be confused with other colorless, acicular or prismatic minerals; microscopic or spectroscopic analysis is used to confirm identity. The explicit etymology linking the mineral to Latin roots is a straightforward example of descriptive mineral nomenclature (Latin origin). For additional reference material consult broader mineral listings and locality reports (database and photographic records).