Browse Items (264 total)

Compare with cryptocrystalline.

Have a look at the alkali granite (L100) and the hornblende biotite granite (L102) in the 1A Reference Series.

Taxonomy Phylum: Mollusca Class: Cephalopoda Diagnostic features Simple suture Chambers Central siphuncle Straight, curved or coiled shell Stratigraphic range Cambrian to recent Straight forms: Cambrian to Permian Coiled forms: Devonian to…

Formula (Mg,Fe)2[SiO4] Structure Orthosilicate Crystal System Crystal system: orthorhombic (+) (-) Physical Properties Colour in hand specimen: pale greenCleavage: none, instead it has characteristic curving cracksHardness: 7 Optical…

Have a look at the oolitic ironstone (L361) and the oolitic limestone (L353) in the 1A Reference Series.

Formula (Mg,Fe)2Si2O6 Structure Chain silicate Crystal System Crystal system: orthorhombic (+) (-) Physical Properties Colour in hand specimen: black Cleavage: two at 90° Hardness: 5-6 Optical Properties Colour in plane polarised…

Have a look at the muscovite mica (M301, M302) in the 1A Reference Series.