Glerhallavík (Chalcedony Cove) is a small cove on the western coast of Skagafjörður in northern Iceland that gets its name from the pebbles of milky and green-flecked chalcedony that litter the beach. It is a protected nature area and picking chalcedony is forbidden. The trail starts near the Guesthouse Reykir on Reykjaströnd, which can be reached by car. Walk past the farm remnants down to Sandvík and Glerhallavík coves. There are patches of coarse beach gravel along the way, so make sure to bring suitable footwear.