Minerals and Mineralogy

What this unit covers

The page brings together material on how minerals are defined, grouped and identified. The note Characteristics of Rock Forming Minerals opens with the basics: a mineral is a naturally occurring chemical compound with a definite composition and crystalline structure. Other resources move into silicate groups, mineral formulas, crystal habits, Bowen's Reaction Series and phase diagrams.

Where to start

Begin with the basics, then move to identification.

1. Read the note on rock-forming minerals for the core definition.
2. Work through the Geology WJEC GCSE Revision Flashcards, which ask what a mineral is, how hardness is tested, what a streak test is and what lustre means.
3. Open the mind map The properties of the minerals, which sets out colour, lustre, hardness and cleavage in short branches.

Identifying specimens

Once the properties feel familiar, try the identification material. The Mineral Identification mind map sorts minerals into silicates, oxides, sulphates, sulphides, carbonates and halides, with examples such as olivine, biotite mica, quartz, haematite and gypsum. The Mineral Flow chart mind map works through relief, colour and alteration to reach an answer. The flashcards on Mineral Identification list key features, such as the two cleavage directions of augite and pyroxene at nearly 90 degrees.

Using quizzes and maps together

Read a map first, then test yourself. The Mineral Identification Self Assessment quiz asks you to name a series of specimens, which shows quickly which features you still mix up. Go back to the map or flashcards for those minerals, then try another quiz. Teachers can use the same pairing for starters and revision tasks.

Where it fits

This unit sits in the Earth Materials strand of Geology and earth sciences. It links naturally to rocks and igneous processes, as the phase diagram flashcards show. Pick one resource that suits your level, try it, and then make your own flashcards or maps for the minerals you find hardest.