Comparison · Sedimentary Rocks
Chert vs Mookaite
Chert and Mookaite are easy to confuse because both are sedimentary rocks. Both sit near Mohs 6.5–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Chert and Mookaite
- Both sit near Mohs 6.5–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Hold a thin edge to the light: Chert is Translucent to opaque, Mookaite is opaque.
- They overlap in white, brown, and red, but Chert also comes in gray, black, and green and Mookaite also comes in yellow and purple.
Chert vs Mookaite properties
| Property | Chert | Mookaite |
|---|---|---|
| Type | Sedimentary Rocks | Sedimentary Rocks |
| Mohs hardness | 6.5–7 | 6.5 |
| Luster | Waxy to dull | waxy |
| Streak | — | White |
| Transparency | Translucent to opaque | opaque |
| Specific gravity | 2.6–2.65 | 2.6 |
| Crystal system | — | amorphous |
| Common colors | Gray, White, Black, Brown, Red, Green | Yellow, Red, Cream, Purple, Brown |
| Rarity | common | uncommon |
| Typical specimen value | $1–$75+ | $5–$160+ |
Which is more valuable?
Mookaite is usually the more valuable of the two: a typical collector specimen runs about $25 against $10 for Chert, and premium Mookaite can reach $160 or more.
About Chert
Chert is a hard, fine-grained sedimentary rock composed almost entirely of microcrystalline or cryptocrystalline quartz, formed either by direct chemical precipitation of silica or by the accumulation and diagenetic alteration of silica-secreting organisms like radiolarians and diatoms. It breaks with a distinctive conchoidal fracture that produces sharp edges, a property that made it invaluable to prehistoric toolmakers. Chert occurs in nodules within limestone and chalk or as bedded layers, and its color varies widely depending on trace mineral impurities.
About Mookaite
Mookaite is a colorful jasper-like trade material from Western Australia, usually showing mustard yellow, red, cream, brown, or purple patches.
Chert vs Mookaite FAQ
Is Chert the same as Mookaite?
No. Both are sedimentary rocks, but they are distinct rock types with different hardness, streak or luster. Both sit near Mohs 6.5–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Chert from Mookaite?
Both sit near Mohs 6.5–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hold a thin edge to the light: Chert is Translucent to opaque, Mookaite is opaque. They overlap in white, brown, and red, but Chert also comes in gray, black, and green and Mookaite also comes in yellow and purple.
Which is harder, Chert or Mookaite?
They are about equally hard, both near Mohs 6.5–7.
Which is more valuable, Chert or Mookaite?
Mookaite is usually the more valuable of the two: a typical collector specimen runs about $25 against $10 for Chert, and premium Mookaite can reach $160 or more.
