Cobalt Snowcap

horses naturally have hooves that will create the mark like that of a horseshoe. in the episode “dragonshy” Rarity pulls out her scarf as an “extra accessory” and hopes she has a tiara that goes with the scarf, to which Rainbow Dash responds, “I think we got bigger problems than making sure our hair bows match our horseshoes”. so, maybe it depends the pony.