What is a reasonable unit of measure of the size of a stone sphere?
A. • Often dealers use weight to define the size of a sphere. Stones spheres are no potatoes, so weight is not a good measure. Not only that, but weight is misleading; a heavy sphere is not necessarily a large sphere. This is because minerals have different specific weights. • The circumference is not a good measure either and tends to be misleading since it is a large number. • Words like big, massive, tremendous, large, very large, small don’t mean much without knowing the diameter of the sphere. • The radius, or better yet, the diameter is a good measure of the size of a sphere. • Inches (“) or millimeters (mm) are commonly used units for the diameter of a stone sphere. • Multiply the size of a sphere given in inches by 25.4 to obtain its size in millimeters.
