Heulandite

Two samples. Largest sample has small granular Heulandite crystals with a slight red hue and vitreous lustre. The smaller sample is of thin white radiating aggregates with a more pearly lustre. Heulandite ((Ca, Na)(Al2, Si7, O18) x 6H2O) can be white, greyish, colourless, greenish or red in colour. Lustre is vitreous but pearly on the cleavage and streak is colourless. Hardness is 3 1/2 to 4 and cleavage is perfect in one direction. Heulandite usually occurs as coffin-shaped crystals or tabular single crystals. Heulandite can also be radiating aggregates with nearly parallel crystals but can also be foliated, globular or granular.