hexagonal

They are a slightly lighter colour than the iconic hexagonal black basalt at the point of the causeway.

Youn and colleagues arranged their seven insulating rods in a kirigami-inspired hexagonal array that, with the turn of a gear, would expand to change the frequency of the higher mode.

All of the medals from the Paris Games also feature an 18-gram, hexagonal piece of wrought iron from the Eiffel Tower.

"I wanted to find a particular roofing slate type, which tends to be hexagonal, with a long point on," he said.

The Olympic and Paralympic medals in Paris are being embedded with pieces from a hexagonal chunk of iron taken from the tower.