from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Hard and fine stones in general, as used for inlay etc. and distinguished from the softer stones used in building.
from the GNU version of the Collaborative International Dictionary of English
- Hard and fine stones in general, such as are used for inlay and the like, as distinguished from the softer stones used in building; thus, a Florentine mosaic is a familiar instance of work in pietra dura, though the ground may be soft marble.
from The Century Dictionary and Cyclopedia
- Ornamental work in inlay of hard stones, such as agates and jaspers, especially when on a somewhat large scale.
Italian, hard stone. (Wiktionary)