Adamant
Adamant and similar words are used to refer 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 αδαμαστος, meaning "untameable".
Adamantite and
adamantium are also common variants.
Adamantine has, throughout ancient history, referred to anything that was made of a very hard material. Virgil describes Tartarus as having a screeching gate protected by columns of solid adamantine. Later, by the Middle Ages, the term came to refer to diamond, as it was the hardest material then known, and remains the hardest non-synthetic material known. It was in the Middle Ages, too, that adamantine hardness and the lodestone's magnetic properties became confused and combined, leading to an alternate definition in which "adamant" means magnet, falsely derived from the Latin
adamare, which means to love or be attached to. Another connection was the belief that adamant could block the effects of a magnet. This was addressed in chapter III of Pseudodoxia Epidemica, for instance.