An enhydro is a quartz nodule or crystal containing a trapped pocket of ancient water, often with an air bubble that moves when the specimen is tilted. It is found within agate geodes or sedimentary deposits where silica-rich fluid was sealed in during crystal growth. Collectors prize it as a portable, prehistoric reservoir.

Hardness
7
Mohs
Luster
Vitreous
Streak
White
Transparency
Transparent

Is this enhydro?

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 enhydro with a known reference. Enhydro 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. Enhydro leaves a white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Enhydro typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: colorless, white, brown, yellow.
  • 5
    Look at form & habit
    Crystal system: trigonal. Typical habit: nodular.

Often confused with

Enhydro vs. its common look-alikes, and how to tell them apart in the field.

Often found alongside enhydro

Minerals reported to co-occur with enhydro. 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
Transparent
Crystal system
Trigonal
Crystal habit
Nodular
Cleavage
None
Rarity
Uncommon
Uses
Collector
Host rock
Hydrothermal Veins

Where rockhounds find enhydro

1 mapped spots

Classic worldwide localities

  • Uruguay
  • Brazil
  • China
  • United States

Field-hunting tip

Look in hydrothermal veins country, the host setting where enhydro typically forms. If you start seeing quartz, calcite, chalcedony in float, you are in the right ground. Field specimens usually show a nodular habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Florida. Start trip planning there.

Common questions

How do you identify enhydro?+
Mohs hardness is 7. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, brown, yellow.
Where is enhydro found?+
Notable localities include Uruguay; Brazil; China; United States.
Can I find enhydro in the United States?+
RockHoundR maps 1 enhydro rockhounding spots across 1 U.S. states. The top states are Florida.
What rocks look like enhydro?+
Enhydro is most often confused with Agate, Quartz. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with enhydro?+
Enhydro commonly co-occurs with Quartz, Calcite, Chalcedony. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does enhydro form in?+
Enhydro typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.
What is enhydro used for?+
Enhydro is used in collector.

Find enhydro on the map

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

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