Blue - Dark Blue Crystals

Usually blue with white veining; allochromatic; found in igneous rock; generally seen in massive form but does form dodecahedral crystals

This corundum can be various colours but commonly known as blue; second hardest mineral known to humans; has enchanted many collectors and jewellers for a long time

History that dates over 5,000 years; prized by pharaohs of ancient Egypt; rock rather than crystal; main component is blue lazurite; deep blues with white and gold flakes; genuine stones have a whitish glow under UV light

Popular crystal; forms when copper ores oxidize; in Middle Ages powder form was used as blue pigmentations in paints and dyes; crystals are soft

Unusual stone; found in metamorphic rocks rich in aluminum; often inter grown with quartz; used in industry for lining furnaces; has dark speckles and pink and brown areas; rich range of blue, brown, and violet tones

Forms in thin, blade like crystals that often radiate from center; found in metamorphic rock; white/grey variety is called 'rhaeticite'; unique hardness; also known as 'disthene' meaning "two strengths"

Form of dolerite found only in the Preseli Mts of Pembrokeshire in Wales; composition varies; composed mostly of calcium feldspar and augite; used to build inner circle of Stonehenge