Apophyllite

Greenish cube-like subhedral Apophyllite on white, bladed aggregates of Stilbite. Apophyllite (KCa4Si8O20(F,OH) x 8H2O) can be colourless, white, grey, greenish, yellowish or reddish in colour. Streak is white and lustre is vitreous and pearly on the cleavage. Hardness is 4 1/2 to 5. Apophyllite usually occurs as cube-like or tabular crystals that are square in cross section. Can also occurs as lamellar, granular or compact. Stilbite (NaCa2Al5Si13O36 x 16H2O) is white, greyish, yellowish, red or brown. Lustre is vitreous and pearly on the cleavage and streak is colourless. Hardness is 3 1/2 to 4 and cleavage is perfect in one direction. Stilbite usually occurs as bladed aggregates of twinned crystals but can also be "wheat sheaves". Stilbite can also be radial, globular or tabular crystals (rare).