How to identify Sulfur

To correctly identify Sulfur (Sulfur), check each of these features in order. Many rocks and minerals look alike, so cross-reference multiple properties before deciding.

Step-by-step identification

1. 1

   Color

   Overall color and any zoning or banding

   Bright yellow, lemon-yellow, honey-yellow, yellowish-brown, greenish-yellow, or grayish-yellow. The color can be altered by impurities.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Resinous to greasy, sometimes dull or earthy in massive forms.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Typically massive, granular, earthy, or stalactitic. Well-formed crystals are often dipyramidal or tabular.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Orthorhombic system. Crystals are typically bipyramidal, tabular, or prismatic. Also occurs as massive, granular, earthy, reniform, stalactitic, or encrusting aggregates.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Poor to indistinct on {001} and {110}. Fracture is more prominent than cleavage.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Volcanic fumaroles and solfataras, hot springs, sedimentary evaporite deposits (especially associated with salt domes and gypsum/anhydrite beds), and as an alteration product of sulfide minerals in hydrothermal veins or sedimentary rocks rich in organic matter.

Key Facts

Hardness

1.5-2.5 on the Mohs scale

Specific Gravity

2.07-2.09 g/cm³

Crystal System

Orthorhombic

Color

Bright yellow, lemon-yellow, honey-yellow, yellowish-brown, greenish-yellow, or grayish-yellow

Luster

Resinous to greasy, sometimes dull or earthy

Transparency

Transparent to translucent to opaque

Fracture

Conchoidal to uneven

Cleavage

Poor to indistinct on {001} and {110}

Composition

Elemental sulfur (S)

Physical characteristics

• Crystal Habit: Bipyramidal, tabular, prismatic; also massive, granular, earthy, reniform, stalactitic, encrusting
• Cleavage Type: Poor/Indistinct
• Fracture Type: Conchoidal to uneven
• Tenacity: Brittle
• Luster Type: Resinous to greasy

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