Postage stamps depicting Icelandic minerals
- In 1998-1999, Iceland Post issued a series of postage stamps depicting the minerals of Iceland. These are the only Icelandic stamps to feature minerals. Four mineral samples from the IINH Mineral Collection are featured on these stamps: scolecite, stilbite and heulandite from Teigarhorn in Berufjörður Fjord and Iceland spar (a variety of calcite) from Helgastaðir in Reyðarfjörður Fjord.
- Iceland has long been famed for its beautiful zeolites – scolecite, stilbite and heulandite in particular. These minerals form over time in rock cavities and fissures and can be found in old basalt strata at various locations, although they are most common in the East Fjords. Teigarhorn is the best-known zeolite site in Iceland.
- Scolesite (CaAl2Si3O10.3H2O) forms quadrilateral, oblong crystals, typically white or semi-transparent. These thin crystals grow in masses and radiate out from a single point. They can be up to 12 cm long.
- Stilbite (NaCa2Al5Si13O36.14H2O) forms flat, white crystals with a pearly lustre. Crystals, up to 7 cm long, tend to widen and thicken towards their ends and form bundles or sheaves.
- Heulandite (CaNaAl4Si15O36.12H2O) also forms flat, white or semi-transparent crystals with a pearly lustre. Crystals often form sheaves. Individual crystals can be as long as 10 cm.
- Another location famous for its minerals is Helgustaðir in Reyðarfjörður Fjord. It is here that so-called Iceland spar, a variety of calsite (CaCO3), was mined from the 17th century until the 20th century. Calcite often forms scalenohedronal crystals. The largest calcite crystal found at Helgustaðir is around 60 cm long.
|Heulandite from Teigarhorn.
||Calcite from Helgustaðir.