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.

Hardness
7
Mohs
Luster
Vitreous
Streak
White
Transparency
Translucent

Is this cactus quartz?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try 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.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Cactus Quartz leaves a white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Cactus Quartz typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: purple, white, yellow, gray, citrine.
  • 5
    Look at form & habit
    Crystal 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
Typical price
$10-150 depending on size and crystal definition

Where rockhounds find cactus quartz

Classic worldwide localities

  • Magaliesberg Mountains, South Africa
  • Boekenhouthoek, South Africa

Field-hunting tip

Look in hydrothermal veins in rhyolite or quartzite country — that is the host setting where cactus quartz typically forms. If you start seeing hematite, goethite, lepidocrocite in float, you are in the right ground. Field specimens usually show a drusy-covered prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify cactus quartz?+
Mohs hardness is 7. It typically shows a vitreous luster. The streak is white. Common colors include purple, white, yellow, gray.
Where is cactus quartz found?+
Notable localities include Magaliesberg Mountains, South Africa; Boekenhouthoek, South Africa.
How much is cactus quartz worth?+
Typical asking prices fall in the range of $10-150 depending on size and crystal definition. Quality, size, and provenance can move individual specimens well outside that range.
What rocks look like cactus quartz?+
Cactus Quartz is most often confused with Amethyst, Quartz, Dogtooth Calcite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with cactus quartz?+
Cactus Quartz commonly co-occurs with Hematite, Goethite, Lepidocrocite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does cactus quartz form in?+
Cactus Quartz typically forms in hydrothermal veins in rhyolite or quartzite. Working float back to the host body is the standard way to chase a fresh occurrence.
What is cactus quartz used for?+
Cactus Quartz is used in collector, decorative.

Find cactus quartz on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.

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