Where can I find Silica in Hürtgenwald?

Silica can also be found in these cities:

Aachen Alsdorf Düren Eschweiler Herzogenrath Kreuzau Langerwehe Mechernich Monschau Nideggen Niederzier Nörvenich Stolberg Vettweiß Würselen Zülpich

You can also find this in Hürtgenwald:

Butter Bread Cornstarch Spread Sweet Food For A Low Cholesterol Diet Pasta Dishes Fruit Juices Instant Cappucino Breakfast Croissants Canned Food