silex

Flint.

A finely ground relatively pure form of silicas used as a paint filler etc.

Every little cold gust that I observed in the Colorado country had this corkscrew character […] an auger, of diameter varying from an inch to a thousand feet, capable of altering its direction so as to bore curved holes, revolving with incalculable rapidity, and armed with a cutting edge of silex.

A vacuum coffee maker.

The Navy uses several types of coffee makers – urns, silexes, and percolators. Each type requires special care in making good coffee.

Remembering my daily habits, Papa-san brewed the coffee and before I had completed a local phone call, he was serving it piping hot from the Silex, still grinning as he thought of other days of coffee-making.