A barbuta (also spelled: barbute or barbut) is a visorless war helmet of fifteenth century Italian design, often with distinctive "T" shaped or "Y" shaped opening for the eyes and mouth. The barbute resembles classical Greek helmets and may have been influenced by a renewed interest in ancient artifacts. Adaman (more commonly: adamant) refers to any especially hard substance, whether composed of diamond, some other gemstone, or some type of metal. Both adamant and diamond derive from the Greek word adamas, meaning "untameable".