Test for purity Crossword Clue

 The crossword clue for "test for purity" is most likely ASSAY.

An assay is a test to determine the purity of a substance. It is often used to test the purity of gold, silver, and other precious metals. Assays can also be used to test the purity of food, water, and other materials.

Here are some examples of how the clue "test for purity" could be used in a crossword puzzle:

Test for purity (5 letters)

Way to determine the purity of a substance (5 letters)

What a jeweler might use to test the purity of gold (5 letters)

I hope this helps!