Headdresses are also an integral part of a ', often encrusted with costume jewelry (such as paste and rhinestones) or real precious stones, to symbolize the spiritual wealth of the saint. The most common headdress for images is the ' (halo) behind or above the head, while regal figures wear an additional ' (crown or coronet). A halo decorating the perimeter of the face, known as a ' or ', is commonly found but not restricted to images of Mary, mother of Jesus. Images of Jesus are identified with the ', a set of three rays protruding from the head at acute angles, and these are never used for any other subject. Triangular haloes are exclusive to rare images of the Trinity, and some saints occasionally bear a ', moon-shaped headband. While there are cheap plastic crowns, haloes, and other metal accessories associated with ', others are made of aluminium or, traditionally, tin (tinwork remains a major folk art form in general in Mexico and New Mexico). These adornments are sometimes gold-plated for a richer effect. A more expensive type in the Philippines is made of solid brass, and ' (Tagalog for 'hammered') by an artisan. The costliest type of crowns are those made of solid sterling silver or gold, often reserved for wealthy clerics and cathedrals. Another style is called ', referring to dented holes placed on gold or silver foiling on the halos or the body of a statue, creating a reflective effect when placed in the light.