STONE STANDARD

For many years, curling stones came in all sorts of shapes and sizes. While there was an attempt made to somewhat standardize the stones over time, in the early 1800s the Grand Caledonian Curling Club came up with a scale for the ratio of diameter to thickness, shown below. Prior to this scale, rocks were often twice as wide as they were thick.

 

The Scale

When the weight of the stone is under the maximum height not to be more than

35 lbs	4.25 inches
38 lbs	4.5 inches
41 lbs.	4.75 inches
44 lbs.	5 inches
47 lbs.	5.25 inches
50 lbs.	5.5 inches

“Whatever the diameter or weight, the height ought never to exceed 6 1/8 inches, nor be less than 4¼ inches. None [ought] to be allowed in a set game of greater diameter than 12 inches, nor of a greater weight than 50 lbs. Imperial.”