Agatized Cycad Wood is a fossilized remain of ancient cycads where organic material has been replaced by microcrystalline silica. Collectors look for well-defined internal structure, such as the characteristic pith, cortex, and vascular bundles visible in polished cross-sections.

Hardness

6.5-7

Mohs

Luster

Waxy

Streak

White

Transparency

Translucent

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Agatized Cycad Wood

Also: Silicified Cycad, Petrified Cycad

Hardness: 6.5-7
Luster: Waxy
Streak: White
Transparency: Translucent

Is this agatized cycad wood?

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 agatized cycad wood with a known reference. Agatized Cycad Wood sits at Mohs 6.5-7, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Agatized Cycad Wood leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Agatized Cycad Wood typically shows a waxy luster.
4
Match the color range
Compare against the expected color range: brown, tan, gray, white, black, red.
5
Look at form & habit
Typical habit: massive.

Often confused with

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

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Wood Opal

Mohs 5.5-6.5

How to tell apart: Luster reads waxy on Agatized Cycad Wood and vitreous on Wood Opal.

Often found alongside agatized cycad wood

Minerals reported to co-occur with agatized cycad wood. 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: 2.6-2.7 g/cm³
Colors: Brown Tan Gray White Black Red
Streak: White
Luster: Waxy
Transparency: Translucent
Crystal habit: Massive
Cleavage: None
Rarity: Uncommon
Uses: Lapidary, Collector, Decorative
Host rock: Sedimentary Strata
Typical price: $10-200 depending on preservation and coloration

Where rockhounds find agatized cycad wood

Classic worldwide localities

Black Hills, South Dakota USA
Utah, USA
Wyoming, USA
Madagascar

Field-hunting tip

Look in sedimentary strata country, the host setting where agatized cycad wood typically forms. If you start seeing quartz, chalcedony, jasper 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.

Common questions

How do you identify agatized cycad wood?+

Mohs hardness is 6.5-7. It typically shows a waxy luster. The streak is white. Common colors include brown, tan, gray, white.

Where is agatized cycad wood found?+

Notable localities include Black Hills, South Dakota USA; Utah, USA; Wyoming, USA; Madagascar.

How much is agatized cycad wood worth?+

Typical asking prices fall in the range of $10-200 depending on preservation and coloration. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like agatized cycad wood?+

Agatized Cycad Wood is most often confused with Wood Opal, Flint Nodules, Chalcedony. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with agatized cycad wood?+

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

What kind of rock does agatized cycad wood form in?+

Agatized Cycad Wood typically forms in sedimentary strata. Working float back to the host body is the standard way to chase a fresh occurrence.

What is agatized cycad wood used for?+

Agatized Cycad Wood is used in lapidary, collector, decorative.

Find agatized cycad wood on the map

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