Ellensburg Blue Agate is a highly sought-after variety of microcrystalline quartz renowned for its distinct cornflower blue color and exceptional translucency. It is found exclusively in the volcanic soil and basalt formations near Ellensburg, Washington, and typically occurs as water-worn nodules.
Is this ellensburg blue agate?
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 ellensburg blue agate with a known reference. Ellensburg Blue Agate sits at Mohs 6.5-7 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Ellensburg Blue Agate leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Ellensburg Blue Agate typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: blue, cornflower blue, violet-blue.
- 5Look at form & habitCrystal system: trigonal. Typical habit: nodular.
Often confused with
Ellensburg Blue Agate vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside ellensburg blue agate
Minerals reported to co-occur with ellensburg blue agate. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂
- Mohs hardness
- 6.5-7
- Density
- 2.65 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Nodular
- Cleavage
- None
- Rarity
- Rare
- Uses
- Gemstone, Lapidary, Collector
- Host rock
- Basalt Flows
- Typical price
- $50-500+ per gram depending on color intensity and quality
Where rockhounds find ellensburg blue agate
Classic worldwide localities
- Kittitas County, Washington, USA
- Ellensburg, Washington, USA
Field-hunting tip
Look in basalt flows country — that is the host setting where ellensburg blue agate typically forms. If you start seeing basalt, zeolites, calcite 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.
Common questions
How do you identify ellensburg blue agate?+
Where is ellensburg blue agate found?+
How much is ellensburg blue agate worth?+
What rocks look like ellensburg blue agate?+
What minerals are found with ellensburg blue agate?+
What kind of rock does ellensburg blue agate form in?+
What is ellensburg blue agate used for?+
Find ellensburg blue agate on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
