How much does a curling stone weigh?

Curling stones do not appear heavy to a viewing audience, but they actually weigh about 42 pounds. Curling stones are made of impact resistant granite from Ailsa Craig - an island in Scotland that looks quite similar to a curling stone. Here, we will briefly explore the weight variation of a curling stone, and understand how a curling stone is manufactured.
A curling stone weighs about 42 pounds. Roughly speaking, it can weigh a little more or a little less than 42 pounds. At the lower and upper extremes, curling stones can weigh between 40 and 44 pounds. This is due to the manufacturing processes of a curling stone. It is important to realize that a curling stone starts out as a slab of granite and then becomes are curling stone by constantly removing material from the stone.
Materials
Curling stones are made of granite. The granite used, however, is different from typical granite used in furniture as it is much more impact resistant. This special type of granite comes from an island in Scotland, Ailsa Craig (which coincidentally happens to look like a curling stone). There is quite a bit of processing required to produce a curling stone, which will be detailed in the next section.
In addition to the granite 'body', each curling stone will receive a plastic handle. These handles are usually red or yellow, but there are ones that are colored blue or green. If desired, the consumer may wish to engrave some sort of message or name on the handle. Stuck on to the handle are small, circular stickers containing a letter in one circle (by the front of the handle), and two other stickers that contain a number between 1 and 8 (by the sides of the handle). These stickers are on the stone so that the stone can be easily identified. Even though every curling stone looks the same, each one has slightly different characteristics in how it "plays" on the ice. Being able to identify a specific stone is very helpful throughout a game of curling.