andrewpreece wrote:
Sharp sand is gritty to the touch, the grains are angular, in my neck of
the woods it is a light grey colour. Builder's sand is also known as soft
sand and is usually a golden colour, soft to the touch, staining your
fingers yellow, and made up of many different sizes of rounded particle,
down to clay size. It is good for bricklaying and mortar.

Am I right in thinking that sharp sand is mostly quartz with similar grain
size (from aeolian or water deposits - think sandy beach) whilst builder's
sand is mechanically ground up rock (of any provenance) with a large
proportion of feldspar minerals which will get hydrated to clays in short
order? So in other words you're just adding more clay?

Theo