Moganite is a polymorph of silica that occurs as a microcrystalline intergrowth within chalcedony and agate. It is difficult to distinguish from quartz without advanced laboratory methods like X-ray diffraction, often appearing as an inconspicuous grayish component of common chalcedony.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineraluncommonQuartz family

Mogánite

Hardness: 6
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this mogánite?

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 mogánite with a known reference. Mogánite sits at Mohs 6, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Mogánite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Mogánite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: gray, white, colorless.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: microcrystalline aggregates.

Often confused with

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

mineral

Quartz

Mohs 7

How to tell apart: Quartz is the harder of the two (Mohs 7 vs. 6).

How to tell apart: Luster reads vitreous on Mogánite and waxy on Chalcedony.

Often found alongside mogánite

Minerals reported to co-occur with mogánite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: SiO₂
Mohs hardness: 6
Density: 2.64 g/cm³
Colors: Gray White Colorless
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Microcrystalline Aggregates
Cleavage: None
Rarity: Uncommon
Uses: Collector, Scientific Research
Host rock: Hydrothermal Cavities
Typical price: $10-50 per specimen

Where rockhounds find mogánite

Classic worldwide localities

Gran Canaria, Spain
Brazil
Czech Republic
USA

Field-hunting tip

Look in hydrothermal cavities country, the host setting where mogánite typically forms. If you start seeing quartz, chalcedony, opal in float, you are in the right ground. Field specimens usually show a microcrystalline aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify mogánite?+

Mohs hardness is 6. It typically shows a vitreous luster. The streak is white. Common colors include gray, white, colorless.

Where is mogánite found?+

Notable localities include Gran Canaria, Spain; Brazil; Czech Republic; USA.

How much is mogánite worth?+

Typical asking prices fall in the range of $10-50 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like mogánite?+

Mogánite is most often confused with Quartz, Chalcedony, Opal. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with mogánite?+

Mogánite commonly co-occurs with Quartz, Chalcedony, Opal, Calcite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does mogánite form in?+

Mogánite typically forms in hydrothermal cavities. Working float back to the host body is the standard way to chase a fresh occurrence.

What is mogánite used for?+

Mogánite is used in collector, scientific research.

Find mogánite on the map

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