Mordenite is definitely a must have especially for the dedicated zeolite collector. Color is colorless, white, yellow, pink and red. Luster is vitreous to silky and pearly. Crystals are transparent to translucent. Crystal Habits include sprays of radial acicular crystal clusters that can remind someone of pin-cushions or snowballs.
Individual crystals are prismatic to acicular and striated vertically.
Aggregates can be radiating, fibrous, columnar and encrusting. Hardness is 4 - 5. Streak is white. Associated Minerals are quartz , calcite , chabazite , natrolite , heulandite , stilbite and other zeolites . Best Field Indicators are crystal habit, color, low density and associations.