Formula(H3O)Fe3+ 3 (SO4)2(OH)6
OriginLavrion (Greece)  
Descriptiongolden yellow massive piece of many small hydronium jarosite crystals
Classification (Lapis) Sulfates
Crystal Systemhexagonal
Hardness4,0 – 4,5
Colourbright yellow to pale yellow
Streakwhite 
Luminescencenone observed 
Lusterdull
Transparency (Opacity)translucent
Cleavageperfect
Fractureuneven to conchoidal
Magnetismnegative
Geological Settingthe oxidized zone of rapidly weathering sulfide-bearing rocks
Specific Gravity3,01 g/cm3