What is the finest sand you can buy?

The finest sand you can buy commercially is often called very fine sand, ultra fine sand, or silica flour, with grain sizes below 0.1 millimeters. For general consumer purchase, the finest readily available sand is play sand that has been washed and screened to a fine texture, or masonry sand which is very fine and soft, often called mason sand or beach sand, with grains around 0.1 to 0.25 millimeters. For even finer sand, you can buy industrial silica sand, also called silica flour, ground silica, or 200 mesh sand, which feels like powder and is used for glassmaking, sandblasting, and epoxy. For aquariums, the finest sand is oolite sand or sugar fine sand which is extremely soft and powdery, often used for reef tanks. For crafts, the finest sand is often sold as fine craft sand or fairy dust sand used for sand art. In the laboratory classification, silt is finer than sand, but among true sands, very fine sand is the finest category before it becomes silt. If you want the softest feel, look for washed, double-screened play sand or ultra fine quartz sand from a masonry supplier, which feels silky and almost like flour between your fingers.