Depending on the type in question, a cubic foot of sand can weigh anything from 90 lb. per cubic foot to 130 lb. per cubic foot. Assuming common dry sand, the weight would be around 100 lb. per cubic foot.
There are different types of sand, and each type has its own specific gravity. Depending on the varying value of specific gravities, equal volume of different types of sand would weigh differently. For example, wet sand weighs approximately 120 lb. per cubic foot and has a specific gravity of 1.92, while dry sand weighs about 100 lb. per cubic foot and has a specific gravity of 1.60.