Aurichalcite
Aurichalcite is a carbonate mineral, usually found as a secondary mineral in copper and zinc deposits. Its chemical formula is (Zn, Cu)₅(CO₃)₂(OH)₆. The zinc to copper ratio is about 5:4. Copper gives aurichalcite its green-blue colors. Wikipedia
Luster: Pearly, silky
Color: Pale green, greenish blue, light blue; colorless to pale blue, pale green in transmitted light
Crystal class: Prismatic (2/m); (same H-M symbol)
Crystal system: Monoclinic
Formula (repeating unit): (Zn,Cu)52
IMA symbol: Ach
Mohs scale hardness: 2