GCSE Geology Mineral Guide Click anywhere on the

GCSE Geology Mineral Guide Click anywhere on the screen to move on. GCSE Geology

GCSE Mineral Guide Minerals on the GCSE Data Sheet GCSE Geology

Quartz (silicate) Glassy lustre Hardness 7, not scratched by steel No cleavage but shows conchoidal fracture Hexagonal crystals terminated by pyramids 5 mm Rose quartz showing conchoidal fracture GCSE Geology

Feldspar (Orthoclase) (silicate) Hardness 6, not scratched by steel 2 cleavages at 90°results in blocky shape Light orange or pinkish in colour Glassy lustre 2 cm GCSE Geology

Feldspar (Plagioclase) (silicate) 1 cm Hardness 6, not scratched by steel 2 cleavages at 90° results in blocky form Creamy white or grey in colour Glassy lustre GCSE Geology

Mica (Biotite) (silicate) Hardness 2. 5 scratched easily by a copper coin Shows one good cleavage Has a distinct pearly lustre Brown or black in colour 2 cm GCSE Geology

Mica (Muscovite) (silicate) Hardness 2. 5 scratched easily by a copper coin Shows one good cleavage Has a distinct pearly lustre Greenish, straw or silvery in colour 2 cm GCSE Geology

Augite (silicate) Hardness 5. 5, not scratched by steel 2 cleavages intersecting at 90° Black in colour Glassy lustre GCSE Geology

Olivine (silicate) Hardness 6. 5, not scratched by steel No cleavage Olive green colour Scratches the streak plate Glassy Lustre GCSE Geology

Garnet (silicate) Hardness 7. 0, not scratched by steel No cleavage Red colour Scratches the streak plate Glassy Lustre Found in schists and formed by the regional metamorphism of shale GCSE Geology

Calcite (carbonate) Hardness 3, scratched by a copper coin Perfect rhombohedral cleavage, 3 planes intersect at 60°/120° to give cleavage rhombs Effervesces and gives off carbon dioxide when dilute hydrochloric acid is applied Glassy lustre GCSE Geology

Halite or Rock Salt (halide) Hardness 2. 5, scratched easily by a copper coin Perfect cubic cleavage, 3 planes intersecting at 90° Tastes salty when put on the tongue Glassy lustre GCSE Geology

Galena (sulphide) Perfect cubic cleavage, 3 planes intersect at 90° Hardness 2. 5, easily scratched by a copper coin Lead grey streak Very dense (7. 4) Metallic lustre GCSE Geology

Haematite (oxide) Hardness 5. 5, may just be scratched by steel Red-brown streak Metallic lustre Often occurs as kidney shaped masses with a fibrous internal structure Quite dense 1 cm GCSE Geology