Dachiardite-Ca is a rare zeolite mineral that forms delicate, bladed crystals, often in sheaf-like bundles similar to stilbite. It is primarily found in cavities within volcanic host rocks where hydrothermal fluids have facilitated its growth. Collectors prize it for its unique habit and the challenge of finding well-formed, distinct specimens.
Is this dachiardite-ca?
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 dachiardite-ca with a known reference. Dachiardite-Ca sits at Mohs 4-4.5, 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.
- 4Match the color rangeCompare against the expected color range: white, pink, orange red.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic, pseudo octohedral, twinning common.
Often confused with
Dachiardite-Ca vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside dachiardite-ca
Minerals reported to co-occur with dachiardite-ca. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂(Si₂₀Al₄)O₄₈·13H₂O
- Mohs hardness
- 4-4.5
- Density
- 2.165-2.206 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic, pseudo octohedral, twinning common
- Cleavage
- Perfect on {001}, {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Of hydrothermal origin in basalt, quartz veins, and pegmatites; in hydrothermally altered pumiceous tuffaceous sediments
Where rockhounds find dachiardite-ca
Classic worldwide localities
- Altoona, Wahkiakum Co., Washington, USA
- Cape Lookout, Tillamook Co., and Agate Beach, Lincoln Co., Oregon, USA
- Lower Geyser basin, Yellowstone National Park, Wyoming, USA
- San Piero in Campo, Elba, and on the Alpe di Siusi, Trentino-Alto Adige, Italy
- Zvezdel, Rhodope Mountains, Bulgaria
- Hatsuneura, Ogasawara Islands, Japan
Field-hunting tip
Where it forms: Of hydrothermal origin in basalt, quartz veins, and pegmatites; in hydrothermally altered pumiceous tuffaceous sediments. If you start seeing mordenite, heulandite, ferrierite in float, you are in the right ground. Typical habit: prismatic, pseudo octohedral, twinning common. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify dachiardite-ca?+
Where is dachiardite-ca found?+
What rocks look like dachiardite-ca?+
What minerals are found with dachiardite-ca?+
What kind of rock does dachiardite-ca form in?+
What is dachiardite-ca used for?+
Find dachiardite-ca on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
