Cactus Quartz, often referred to as Spirit Quartz, is characterized by a central prismatic crystal covered in a multitude of smaller, druzy crystals. These pieces are highly sought after by collectors for their unique, spiky appearance and often vibrant purple or yellow coloration caused by inclusions.
Is this cactus quartz?
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 cactus quartz with a known reference. Cactus Quartz sits at Mohs 7, 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: purple, white, yellow, gray, citrine.
- 5Look at form & habitCrystal system: trigonal. Typical habit: drusy-covered prismatic crystals.
Often confused with
Cactus Quartz vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside cactus quartz
Minerals reported to co-occur with cactus quartz. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂
- Mohs hardness
- 7
- Density
- 2.65 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Drusy-covered prismatic crystals
- Cleavage
- None
- Rarity
- Uncommon
- Uses
- Collector, Decorative
- Host rock
- hydrothermal veins in rhyolite or quartzite
Where rockhounds find cactus quartz
Classic worldwide localities
- Magaliesberg Mountains, South Africa
- Boekenhouthoek, South Africa
Field-hunting tip
Where it forms: hydrothermal veins in rhyolite or quartzite. If you start seeing hematite, goethite, lepidocrocite in float, you are in the right ground. Typical habit: drusy-covered prismatic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify cactus quartz?+
Where is cactus quartz found?+
What rocks look like cactus quartz?+
What minerals are found with cactus quartz?+
What kind of rock does cactus quartz form in?+
What is cactus quartz used for?+
Find cactus quartz on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
