Gatewayite is a local variety of chert or chalcedony found near Gateway, Colorado. It typically presents as massive, dull-to-waxy material that is frequently used by lapidaries for polishing and cabochon making due to its high silica content and durability.
Is this gatewayite?
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 gatewayite with a known reference. Gatewayite 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. Gatewayite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Gatewayite typically shows a waxy luster.
- 4Match the color rangeCompare against the expected color range: white, gray, brown.
- 5Look at form & habitCrystal system: trigonal. Typical habit: massive.
Often confused with
Gatewayite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside gatewayite
Minerals reported to co-occur with gatewayite. 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
- Waxy
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Common
- Uses
- Lapidary, Collector
- Host rock
- Sedimentary Formations
- Typical price
- $5-30 for rough specimens
Where rockhounds find gatewayite
Classic worldwide localities
- Gateway, Colorado, USA
Field-hunting tip
Look in sedimentary formations country — that is the host setting where gatewayite typically forms. If you start seeing quartz, calcite, barite in float, you are in the right ground. Field specimens usually show a massive habit, so train your eye for that shape before scanning the outcrop.





