mineral

Sulfur crystals on iron-rich matrix

Native sulfur (S₈), likely with iron oxides/hydroxides such as limonite

AI-generated identification · may be incorrect

Bright yellow to yellow-green, small crystals with resinous to greasy luster; Mohs hardness 1.5–2.5, orthorhombic crystal system, brittle, specific gravity about 2.0–2.1. The brown, rusty matrix appears iron-oxide-rich; exact identification from the image alone is uncertain.

Identified October 1, 2026More mineral →

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Physical properties

Formation & geological history

Sulfur commonly forms around volcanic fumaroles or through microbial reduction of sulfate in sedimentary deposits; associated iron oxides arise from weathering. The specimen’s age and precise setting cannot be determined visually.

Uses & applications

Sulfur is used to make sulfuric acid, fertilizers, and chemicals; attractive crystal specimens are collected, though sulfur is rarely used in jewelry because it is soft and brittle.

Geological facts

Native sulfur can crystallize from volcanic gases and is notably soft enough to scratch with a fingernail; avoid heating or burning specimens, as sulfur fumes can be harmful.

Field identification & locations

Look for vivid yellow crystals, low hardness, and a distinctive sulfur odor when gently rubbed (do not burn it); common sources include volcanic regions and sedimentary evaporite deposits. Similar yellow minerals can be distinguished by testing hardness and crystal habit.