Comparison · Minerals
Astrophyllite vs Crocoite
Astrophyllite and Crocoite are easy to confuse because both are minerals. Both sit near Mohs 3–3.5, 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 Astrophyllite and Crocoite
- Both sit near Mohs 3–3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Astrophyllite leaves a brownish yellow streak on unglazed porcelain, Crocoite leaves orange-yellow.
- Luster is different: Astrophyllite is vitreous to pearly/submetallic sheen while Crocoite is adamantine to vitreous/resinous.
- Crocoite feels noticeably heavier for its size (specific gravity 5.9–6.1 versus 3.3–3.4 for Astrophyllite).
- They overlap in red and orange, but Astrophyllite also comes in yellow and brown.
- Well-formed crystals give it away: Astrophyllite is Triclinic, Crocoite is Monoclinic.
Astrophyllite vs Crocoite properties
| Property | Astrophyllite | Crocoite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 3–3.5 | 2.5–3 |
| Luster | Vitreous to pearly/submetallic sheen | Adamantine to vitreous/resinous |
| Streak | Brownish yellow | Orange-yellow |
| Transparency | Translucent | Translucent |
| Specific gravity | 3.3–3.4 | 5.9–6.1 |
| Crystal system | Triclinic | Monoclinic |
| Common colors | Golden-yellow, Bronze, Copper-red, Brown | Bright orange-red, Red |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$150+ |
Which is more valuable?
Typical specimens of Astrophyllite and Crocoite trade in a similar range, around $20.
About Astrophyllite
Astrophyllite is a rare, structurally complex silicate of potassium, sodium, iron, titanium, and manganese that forms bronze to golden-brown bladed or feathery crystal sprays. Its name, from the Greek for star leaf, describes the radiating star-like clusters it builds within alkaline igneous rocks. The mineral is prized more for its striking metallic sheen and habit than for gem use, since it never occurs transparent.
About Crocoite
Crocoite is lead chromate, PbCrO4, prized for its vivid orange-red color and slender, elongated prismatic crystals that rank among the most vibrantly colored of any mineral. It forms in the oxidized zones of lead deposits where chromium-bearing solutions interact with lead minerals, a fairly uncommon geochemical pairing. It holds historical significance as the first mineral source of the element chromium, discovered and named in the late 18th century.
Astrophyllite vs Crocoite FAQ
Is Astrophyllite the same as Crocoite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Both sit near Mohs 3–3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Astrophyllite from Crocoite?
Both sit near Mohs 3–3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Astrophyllite leaves a brownish yellow streak on unglazed porcelain, Crocoite leaves orange-yellow. Luster is different: Astrophyllite is vitreous to pearly/submetallic sheen while Crocoite is adamantine to vitreous/resinous.
Which is harder, Astrophyllite or Crocoite?
Astrophyllite is harder: Mohs 3–3.5 against Mohs 2.5–3 for Crocoite.
Which is more valuable, Astrophyllite or Crocoite?
Typical specimens of Astrophyllite and Crocoite trade in a similar range, around $20.
