abstract
aperture
art
beautiful
boulder
burrow
cauterization
cautery
cave
cavity
change
character
configuration
contours
coral
corrosion
deteriorate
environment
erode
erosion
feature
figure
grain
hole
isolated
look
loop
manner
material
naturally
nature
niche
object
outline
physically
pore
porous
reef
resource
rock
shape
socket
spongy
stone
stones
story
style
surface
wear away
white