The silk test in construction material?

Question

testing to find the amount silk found in a test sample of sand, with the use of salt water.

Answer 1

The reason you have not received any answers to your question is that there is no silk in sand.  What I think you meant was "testing to find the amount of silt found in a test sample".  Silt being a general term to describe the finer particulate material routinely found in river sediments which are smaller than sand particles.  I do not know of any particular test which uses salt water.