MN618 Sample ID MN618 • Cabinet Z Celestite 16cm W x 26cm H x 7.75cm D • 3454g Sample TypeMineralColorYellow crystals with Grey crystalline base.LusterVitreous StreakYellowCleavage/FracturePerfect Prismatic Cleavage and Uneven FractureSpecific GravitySpecimen was too large to measure. Geographic Location/DateGirgenti Italy Mohs Hardness 2 This specimen was too large to use the calipers and measure specific gravity with. The mineral is a yellow Celestite (also known as 'Celestine') crystalline sample with a grey crystalline base. The specimen is extremely brittle with multiple chunks falling off during testing. It has perfect prismatic cleavage and uneven fracture. The streak is yellow. Fluorescent under UV Light. The flame turns crimson when heated by a flame. Description of Mohs scale here