INDIAN BLACK COLUMNAR BASALT QUARRY A structure that forms in rocks (most commonly in basalt) that consists of columns (mostly commonly hexagonal in shape) that are separated by joints or fractures in the rock that formed when the rock contracted, most often during cooling. Columnar jointing is always a joy to observe in rocks in the field. Stumbling upon perfectly geometric columns of rock can only be described as magical. Even the most austere scientist might find herself (or himself) gaping in awe at the flawless shapes and wondering if men or Gods carved those immaculate columns. However, that majestic columnar jointing can easily be explained with a little bit of physics.