Which is the weight range of a curling stone?
Curling has been a medal sport in the Winter Olympic Games since the 1998 Winter Olympics. It currently includes men's, women's, and mixed doubles tournaments.
The curling stone is made of granite and is specified by the World Curling Federation, which requires a weight between 38 and 44 pounds, a maximum circumference of 36 inches, and a minimum height of 4.5 inches.
Ailsa Craig is the traditional source of stones and produces two types of granite, Blue Hone and Ailsa Craig Common Green. Blue Hone has very low water absorption, which prevents the action of repeatedly freezing water from eroding the stone. Kays of Scotland has been making stones since 1851 and has the exclusive rights to the Ailsa Craig granite. Kays have been involved in providing curling stones for the Winter Olympics since Chamonix in 1924 and has been the exclusive manufacturer of curling stones for the Olympics since the 2006 Winter Olympics.
The playing surface or curling sheet is a rectangular area of ice, carefully prepared to be as flat and level as possible, 146 to 150 feet in length by 14.5 to 16.5 feet in width.
A target, the house, is centered on the intersection of the centre line and the tee line, drawn 16 feet from, and parallel to, the backboard. The house consists of a centre circle (the button) and three concentric rings, of diameters 4, 8, and 12 feet, formed of a colored vinyl sheet under the ice. A stone must at least touch the outer ring in order to score.