Stone
(a) Consists of an iron handle and a cheese-shaped mass of hard stone. (b) It must not weigh more than 44 lbs. (the usual weight is 35 lbs. to 40 lbs), nor measure more than 36 in. in circumference, nor be less than one-eighth of its circumference in height. (c) Material. The most popular material is blue Ailsa Craig, but even better formations are Burnock Water and Crawfordjohn. Other wellknown varieties are Crieff Black, Carsphairn, Crieff Serpentine, and Tinkernhill.
Stones are now generally made with reversible soles, so that the sole may be used which is most suited to condition of the ice.