Search Mineralpedia – A Mineral Photo Database and Identification Guide
Named in honor of Siegmund August Wolfgang von Herder, a mining official of Freiberg, Germany. Herderite is difficult, if not nearly impossible to distinguish from its hydroxyl-dominant analogue hydroxylherderite. While found originally in Germany, the analysis of this initial material is suspect and additional material from the locality is now unavailable. A gem of Herderite from supposedly Brazil is the only known fluorine-dominant Herderite that has been proven via modern analytical methods, so it is likely that most Herderite is actually hydroxylherderite. Herderite will fluoresce violet under ultraviolet light and has a cathodoluminescence and phosphorescence of pink-orange in X-rays.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/herderite.pdf
Named for Germain Henri Hess (1802-1850). Occurs within low to medium temperature vein deposits. Can also be found in massive pyrite deposits. Crystals are usually distorted or irregular, pseudocubic and modified, sectile, opaque grey to dark grey. sometimes shiny silvery. Localities for Hessite include in Romania, Kazakhstan, Russia, Norway, Australia, Fiji, the Philippines, Chile, the United States, Canada, and others.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/hessite.pdf
Named for the Greek words eteros, meaning “hetero” or “different,” and morphi, meaning “form,” in reference to the difference between the mineral and a proposed dimorphous species. Hetermophite is of hydrothermal origin and can be found in Germany, the Czech Republic, Mexico, and newer localities in England, Tajikistan, Slovakia, Romania, Kyrgyzstan, Japan, Hungary, Greece, Bulgaria, Bolivia, and Austria.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/heteromorphite.pdf
Named in honor of John Henry Heuland, an English mineral collector and dealer. Heulandite actually consists of several types which are Heulandite-Ba, -Ca, -K, -Na, and –Sr. The Heulandites are relatively common as a whole and occur in basalt cavities, in weathered andesite and diabase, and as a devitrification product of volcanic glasses and tuffs. It can be found as fine specimens from Iceland, on the Faeroe Islands, Scotland, Switzerland, the United States, Canada, Brazil, India, and Australia among many others.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/heulandite.pdf