Also called the shamrock knot, this is knot #2437 in The Ashley Book of Knots (ABoK). The knot is two four part crown knots overlying each other with the second crowning running in the opposite direction to the first. A similar knot which some call the Japanese good luck knot can also be tied with the crown knots running in the same direction giving the knot a slightly different appearance. The Chinese often attached meaning to their different knots they crafted. This one universally seems to have a meaning of good luck as sailors also often tied it for a good luck charm.
This knot could be used as a pendant for a knot necklace, stitched onto a pillow for decoration. A decoration on a tied parcel or the top loop could be made longer and ring hitched onto a key ring to make a unique key fob.