Browse Items (264 total)

Have a look at the amygdaloidal basalt (L161) in the 1A Reference Series.

Have a look at the granodiorite (L120) for anhedral quartz, biotite and plagioclase.

Formula CaSO4 Structure Non-silicate Crystal System Crystal system: orthorhombic (+) Physical Properties Colour in hand specimen: white or colourless when pure Cleavage: two at 90° Hardness: 3-3.5 Optical Properties Colour in plane…

Compare with isotropic.

Formula Ca5(PO4)3(OH,F,Cl) Structure Non-silicate Crystal System Crystal system: hexagonal (-) Physical Properties Colour in hand specimen: green, white, yellow, blue brown etc.Hardness: 5 Optical Properties Colour in plane polarised…

Have a look at the argillaceous limestone (L350) in the 1A Reference Series.

Taxonomy Phylum: Mollusca Class: Cephalopoda Subclass: Coleoidea Cohort: Belemnoidea Diagnostic Features Diagram with labelled features of belemnites 'Bullet' shape Phragmocone: chambers divided by aragonitic septa (often preserved as conical…

Taxonomy Phylum: Mollusca Class: Bivalvia Diagnostic features Palial line/palial sinus Adductor muscle scars Growth lines Dorsoventral symmetry (some exceptions, for example Gryphaea) Two hinged valves Umbo Hinge Gills (rarely…