Teigarhorn, East Iceland (Zeolites)
This area of Iceland is a bounty of interesting rocks, minerals, and crystals. This plaque provides information about zeolites. It reads:
ZEOLITES AT TEIGARHORN
Teigarhorn is a world-famous site for zeolites. They are first mentioned in connection with Berufjöður in the 18th century. There, as in many other places, zeolites are found in hollows and crevices in the rock, coming to light as a result of erosion, particularly when wave action breaks rock out of cliff faces. In many places, these cavity filings are found in clay-like material and are easily destroyed. They are often covered with an external layer of blue-green celadonite. In geological terms, the zeolite formations at Teigarhorn are connected to dikes extending from the main volcano that was active in Álftafjörður more than 10 million years ago. Teigarhorn is best known for the types scolecite, stilite, heulandite, and mordenite, along with epistilbite, which was first identified in samples from there. Local merchants and others used to cater rocks indiscriminately here and sell samples around the world. In 1976m the Environment Agency, in consultation with the landowners, declared Teigarhorn a natural monument. No natural formations may be disturbed here, and protected areas can only be visited after obtaining authorization from the supervisor who lives on the farm.