flinty
An aroma and flavor reminiscent of flint striking steel, also referred to as gunflint. This characteristic, which the French call pierre-à-fusil, comes from grapes grown in certain soils and is considered a positive trait. It’s found in extremely dry white wines such as certain French Chablis and Sauvignon blancs.
The New Wine Lovers Companion, 2nd Edition, by Ron Herbst and Sharon Tyler Herbst. Copyright © (1) 2003, 1995 by Ron Herbst and Sharon Tyler Herbst. Reprinted by arrangement with Barron's Educational Series, Inc.