blue bright clouds colored colorful column dawn gold golden group horse muse pastel pegasus pillar sky statue sunrise sunset accumulated accumulations aged calcium-carbonate cave cavern caving ceilings coloring colouring columns compounds crystallisation crystallization crystallize deposits distinctive edges formation forms geological geology icicle-like limestone mineral-deposits minerals old Particles pointed shape shaped shapes slow slow-growth slowly smooth speleology speleothems spelunker spelunkering Stalactite stalactites subterranean surface surfaces texture textures Underground unusual