石化した
ancient
animal
cambrian
crystal
detail
dinosaur
echinoid
fossil
fossil sea urchin
gemstone
geological
geology
invertebrate
macraster
mineral
natural
nature
ornamental
paleontology
petrifaction
polished
prehistoric
prehistory
research
rough
science
sea urchin
section
sedimentary
shiny
slice
smoothed
stone
texture
textured
time
triassic
weathered
white