Mineral Guide · Mineral

Greenockite

Greenockite is a rare cadmium sulfide mineral, often forming bright yellow coatings and small crystals in oxidised zinc deposits.

Interactive 3D structure

Crystal structure

Open COD source

Loading interactive structure...

Rotate with the mouse or touch. The cell frame and a, b, c labels show the repeating unit used by the structure model.

Mineral properties

Formula: CdS
Class: Sulfides
Crystal system: Hexagonal
Typical colours: brown, yellow, orange, red
Lustre: Adamantine, Resinous
Hardness: 3.00-3.50
Specific gravity: 4.80-4.90
Crystal habit: Crusty, Granular, Hexagonal
Origin: oxidised zinc deposits and weathering zones associated with sphalerite

What is Greenockite?

Greenockite is a rare cadmium sulfide mineral, often forming bright yellow coatings and small crystals in oxidised zinc deposits.

Mineralogy and structure

Reference formula: CdS. Greenockite has the wurtzite-type hexagonal structure and is commonly associated with smithsonite and sphalerite. Cadmium content makes handling important. Greenockite belongs to the sulfides and has a hexagonal crystal system. Typical hardness is 3–3.5 on the Mohs scale and specific gravity is approximately 4.8–4.9.

Colour and appearance

Typical colours include yellow, orange, red, brown. The usual hexagonal, crusty, granular habit and resinous, adamantine lustre are useful descriptive features, but colour alone is not diagnostic.

Formation and localities

Greenockite forms in or is associated with oxidised zinc deposits and weathering zones associated with sphalerite. Important documented localities include Mexico, the United States, Scotland, Namibia and Kazakhstan.

Collecting and care

Cadmium-bearing display mineral: do not cut or grind, avoid dust and wash hands after handling.

Sources and editorial review

Reviewed by NotOnlyRocks Editorial Team

Last reviewed: 31 August 2026

All mineral guides

Looking for Greenockite?

We don't currently have Greenockite specimens available.

Send us a request and we will try to find a suitable specimen for you.

Request Greenockite