This test is usually carried out on sand stones to examine the presence of calcium carbonate that weakens the weather resisting quality. In this particular test, a sample of stone weighing approximate 50 to 100 gm is taken and kept in a solution of 1% hydrochloric acid for 7 days. The solution is agitated at intervals. A fine building stone maintains its sharp edges and keeps its surface intact. If edges are broken & powder is formed on the surface, it shows the presence of calcium carbonate. Such type of stones will have poor weather resistance.