stones and rocks, are fragments of bedrock and, in the context of soil, the two words are synonymous (see also geology). As visible constituents of the soil or its surface they loom large in the folklore of wine quality. They figure prominently in the older French concepts of terroir. Nineteenth-century French writers such as Rendu and Petit-Lafitte laid particular emphasis on the proportions of stone or gravel in the soils of the best vineyards. The stonier the soil, they said, the better in general is the wine quality.