rhombus

Red Crystal (politically and religiously neutral emblem used by the International Committee of the Red Cross)

rhombus-shaped mochi

flower-shaped family crest

caltrop

caltrop (spiked device scattered to maim infantry and horses)

stitching chisel

rhombencephalon

os trapezium

trapezoid bone

rhombohedron

siderite

smithsonite

magnesite

magnesite

rhombic dodecahedron

large Japanese junk