Krestenitis
Krestenitis is a very rare iron-containing epidote mineral with the chemical formula (Ce,La)(Al,Fe3+)2(SiO4)(Si2O7)O(OH). It belongs to the epidote group of minerals.
Krestenitis is characterized by its distinctive orange-brown to reddish-brown color and its occurrence as small, often euhedral, crystals. It's a relatively uncommon mineral, typically found in skarns and contact metamorphic rocks.
The mineral's name honors Gustav Kresten (1846-1917), an Austrian mineralogist and petrographer.
Because of its rarity and small crystal size, krestenitis is primarily of interest to mineral collectors and researchers. It is not used industrially.
Distinguishing krestenitis from other members of the epidote group, especially allanite, requires careful analysis, often involving electron microprobe or X-ray diffraction techniques due to the similarities in appearance and chemical properties of the rare-earth element content. Its cerium enrichment is a key characteristic.