Comparison · Sulfide Minerals vs Native Elements
Orpiment vs Sulfur
Orpiment and Sulfur are easy to confuse. Both sit near Mohs 1.75, 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 Orpiment and Sulfur
- Both sit near Mohs 1.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Orpiment leaves a pale lemon yellow streak on unglazed porcelain, Sulfur leaves white to pale yellow.
- Orpiment feels noticeably heavier for its size (specific gravity 3.49 versus 2.07 for Sulfur).
- Hold a thin edge to the light: Orpiment is translucent, Sulfur is transparent.
- They overlap in yellow and brown, but Orpiment also comes in orange and Sulfur also comes in green.
- Well-formed crystals give it away: Orpiment is monoclinic, Sulfur is orthorhombic.
Orpiment vs Sulfur properties
| Property | Orpiment | Sulfur |
|---|---|---|
| Type | Sulfide Minerals | Native Elements |
| Mohs hardness | 1.75 | 2 |
| Luster | resinous | resinous |
| Streak | Pale lemon yellow | White to pale yellow |
| Transparency | translucent | transparent |
| Specific gravity | 3.49 | 2.07 |
| Crystal system | monoclinic | orthorhombic |
| Common colors | Lemon yellow, Golden yellow, Orange-yellow, Brownish yellow | Yellow, Bright yellow, Yellowish brown, Greenish yellow |
| Rarity | uncommon | common |
| Typical specimen value | $10–$400+ | $5–$250+ |
Which is more valuable?
Orpiment is usually the more valuable of the two: a typical collector specimen runs about $60 against $35 for Sulfur, and premium Orpiment can reach $400 or more.
About Orpiment
Orpiment is a soft arsenic sulfide mineral famous for its brilliant lemon to golden-yellow color and resinous luster. It forms in low-temperature veins and hot spring deposits, commonly alongside red-orange realgar.
About Sulfur
Sulfur is a native element famous for its bright yellow color. It forms blocky to dipyramidal crystals and earthy crusts around volcanic vents, hot springs, and salt domes, and has a distinctive resinous luster.
Orpiment vs Sulfur FAQ
Is Orpiment the same as Sulfur?
No. Orpiment is a sulfide mineral while Sulfur is a native element. Both sit near Mohs 1.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Orpiment from Sulfur?
Both sit near Mohs 1.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Orpiment leaves a pale lemon yellow streak on unglazed porcelain, Sulfur leaves white to pale yellow. Orpiment feels noticeably heavier for its size (specific gravity 3.49 versus 2.07 for Sulfur).
Which is harder, Orpiment or Sulfur?
They are about equally hard, both near Mohs 1.75.
Which is more valuable, Orpiment or Sulfur?
Orpiment is usually the more valuable of the two: a typical collector specimen runs about $60 against $35 for Sulfur, and premium Orpiment can reach $400 or more.
