Ferrierite-Na is a rare member of the zeolite group often found as delicate bladed, radiating sprays in the vesicles of altered basaltic rocks. Collectors prize it for its unique habit and association with other secondary zeolites in volcanic environments. Look for its characteristic pearly luster and tabular crystal morphology, typically associated with common zeolite minerals.
Is this ferrierite-na?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch ferrierite-na with a known reference. Ferrierite-Na sits at Mohs 3-3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to pearly.
- 4Match the color rangeCompare against the expected color range: white, colorless, pink, orange, red.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: radial, tabular.
Often confused with
Ferrierite-Na vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside ferrierite-na
Minerals reported to co-occur with ferrierite-na. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,K)₅(Si₃₁Al₅)O₇₂·18H₂O
- Mohs hardness
- 3-3.5
- Density
- 2.136 g/cm³
- Streak
- White
- Luster
- Vitreous to pearly
- Transparency
- Transparent to translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Radial, tabular
- Cleavage
- {100}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In seams and vesicles in deeply weathered basalts, flow breccias, and andesites; in tuffaceous sediments
Where rockhounds find ferrierite-na
Classic worldwide localities
- Altoona, Wahkiakum Co., Washington, USA
- Agoura, Los Angeles Co., and on Silver Mountain, southwest of Markleeville, Alpine Co., California, USA
- Kamloops Lake, near Kamloops, and at Monte Lake and Pinaus Lake, near Westwold, British Columbia, Canada
- Albero Basso and Val Timonchio, Vicenza, and near Monastir, Cagliari, Sardinia, Italy
- Weitendorf, near Wildon, Styria, Austria
- Reichweiler, Rhineland-Palatinate, Germany
Field-hunting tip
Where it forms: In seams and vesicles in deeply weathered basalts, flow breccias, and andesites; in tuffaceous sediments. If you start seeing zeolites, plagioclase, hypersthene in float, you are in the right ground. Typical habit: radial, tabular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ferrierite-na?+
Where is ferrierite-na found?+
What rocks look like ferrierite-na?+
What minerals are found with ferrierite-na?+
What kind of rock does ferrierite-na form in?+
What is ferrierite-na used for?+
Find ferrierite-na on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
