Is salt translucent or opaque

A salt is a stable combination of an acid and an alkali. The commonest is our table salt, sodium chloride.

In a well prepared specimen, the cubic nature of this compound will be obvious, but it is translucent rather then transparent, but colourless. Some specimens of Calcite are almost transparent.

Many salts are quite opaque - probably the majority of them.

The silicates present many examples of gem quality salts, and their transparency is part of their attraction.