How to identify Iron Ore

To correctly identify Iron Ore (Hematite or Goethite (Iron Oxide/Hydroxide)), 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

   Hematite: Steel-gray to black (specular hematite), reddish-brown to red (earthy hematite). Goethite: Yellowish-brown, reddish-brown, dark brown to black.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Hematite: Metallic to dull earth. Goethite: Adamantine to dull, silky in fibrous varieties.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Hematite: Massive, botryoidal, reniform, oolitic, micaceous (specularite), earthy. Goethite: Massive, botryoidal, stalactitic, fibrous, earthy.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Hematite: Rhombohedral (trigonal system), often tabular, platy, or granular. Goethite: Orthorhombic, typically acicular, fibrous, or massive.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Hematite: No true cleavage, but parting may be observed parallel to the basal pinacoid and rhombohedral faces. Goethite: Perfect cleavage on {010}, good on {100}.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Hematite: Found in Banded Iron Formations (BIFs), contact metamorphic deposits, hydrothermal veins, and as a weathering product. Goethite: Common in gossans, bog iron ores, lateritic soils, and as a secondary mineral in oxidized zones of ore deposits.

Key Facts

Hardness

Hematite: 5-6.5 on Mohs scale. Goethite: 5-5.5 on Mohs scale.

Specific Gravity

Hematite: 5.26. Goethite: 3.3-4.3.

Crystal System

Hematite: Trigonal. Goethite: Orthorhombic.

Color

Hematite: Steel-gray, black, reddish-brown. Goethite: Yellowish-brown, reddish-brown, dark brown.

Luster

Hematite: Metallic to dull earth. Goethite: Adamantine to dull, silky.

Transparency

Opaque.

Fracture

Hematite: Uneven to subconchoidal. Goethite: Uneven.

Cleavage

Hematite: None (parting present). Goethite: Perfect on {010}, good on {100}.

Composition

Hematite: Iron(III) oxide (Fe2O3). Goethite: Iron oxyhydroxide (FeO(OH)).

Physical characteristics

• Crystal Habit: Hematite: Rhombohedral, tabular, platy, granular, massive, botryoidal, reniform, oolitic, earthy. Goethite: Acicular, fibrous, massive, botryoidal, stalactitic, earthy.
• Cleavage Type: Hematite: No true cleavage, but parting on {1011} and {0001}. Goethite: Perfect on {010}, good on {100}.
• Fracture Type: Hematite: Uneven to subconchoidal. Goethite: Uneven.
• Tenacity: Brittle.
• Luster Type: Hematite: Metallic, submetallic, dull earth. Goethite: Adamantine, silky, dull.

Explore Iron Ore