Nephrite "hei-tiki" (neck pendant). These are believed to have their own "mana", are handed down as valuable heirlooms, and often given as gifts to seal important agreements. It has also been used for a range of tools such as adzes, as Māori had no metal tools before European contact. Commonly called "greenstone", jade jewellery in Māori designs is widely popular with tourists. Stone is often imported from Canada, China and Siberia, and Ngai Tahu runs a pounamu certification scheme to verify the authenticity of New Zealand stone. Nephrite Nephrite is a variety of the calcium, magnesium, and iron-rich amphibole minerals tremolite
Rock of Gibraltar time, dried up during the Messinian salinity crisis. The Atlantic Ocean then broke through the Strait of Gibraltar, and the resultant flooding created the Mediterranean Sea. The Rock forms part of the Betic Cordillera, a mountain range that dominates south-eastern Iberia. Today, the Rock of Gibraltar forms a peninsula jutting out into the Strait of Gibraltar from the southern coast of Spain. The promontory is linked to the continent by means of a sandy tombolo with a maximum elevation of . To the north, the Rock rises vertically from sea level up to at Rock Gun Battery. The Rock's highest