brisling bristling calcium can canned clupeidae edible European-sprats fatty-acids fish food golden health healthy heart-healthy herring-family herring-like marine-fish nonperishable nutrient-rich nutrients nutritious oil oily-fish omega-3 packed polyunsaturated portable potential self-contained-food skipper small smoked sprats sprattus-sprattus tightly-packed tin tinned tins vitamins 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 can-opener breakable brown brown-eggs calcification chicken-eggs colored colors coloured colours cook cooking egg eggs eggshells external farm-fresh fragile fragility fresh fresh-eggs haemoglobin hemoglobin hens-eggs life mottled mottling outer-covering outside oval oviduct ovoid pigmentation pigmented-shells pigmenting protoporphyrin speckled surfacing textured variety various accessible crammed European-sprat open opened pilchards sardines silvery skin sprat tight Dirt earth environment igneous metamorphic Mineral nature object rock science Sed Soil