picromerite

{{Infobox mineral | name = Picromerite | image = Halite-Picromerite-mrz114a.jpg | alt = | caption = Picromerite on halite | category = Sulfate mineral | formula = K2Mg(SO4)2·6H2O | IMAsymbol = Pmr | strunz = 7.CC.60 | dana = 29.03.06.01 | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = P21/a | unit cell = a = 9.07, b = 12.21, c = 6.11 [Å]; β = 104,8°; Z = 2 | color = Colorless; white, grey, reddish, yellowish | habit = massive aggregates; crusts; prismatic crystals | twinning = | cleavage = perfect {01} | fracture = | tenacity = | mohs = 2.5 | luster = Vitreous | streak = White | diaphaneity = Transparent | gravity = | density = 2.03 | polish = | opticalprop = Biaxial (+) | refractive = nα = 1.461 nβ = 1.463 nγ = 1.476 | birefringence = δ = 0.015 | pleochroism = | 2V = Measured: 47° | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = in cold water | impurities = | alteration = | other = | prop1 = Taste | prop1text = bitter | references = }} Picromerite (synonyms: schoenite, schönite) is a mineral from the class of hydrous sulfates lacking additional anions, and containing medium to large cations according to the Nickel–Strunz classification.

== Etymology == The name comes from the Greek words πικρός [pikros] for "bitter" and μέρος [meros] for "part", and relates to the bitter taste of the mineral.