Natural v. Synthetic Tests: Copyright-Protected?

Dear Rich: I have a website that helps people determine whether jewelry and gemstones are natural or synthetic. I am redoing the site and want to eliminate some of the sources listed for the various tests. I've changed the wording so that it is not similar to the source material, but it is still the same test. I would like to know if this is fair use, as many of these tests are standard practice in the industry. Also, we've created something original because we are taking points from various sources and compiling them with our own explanations to create a relatively unique webpage.  

You're not infringing if you are describing common tests and standards used within an industry and you have made an attempt to distinguish yourself from the source material. That is, you are not copying verbatim. Copyright law won't protect "any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied." So, the fact that natural pearls are grittier than fake pearls cannot be copyright-protected. In addition, if there are a limited number of ways of describing the test -- for example, that natural diamonds can cut glass -- you will rarely run into a problem.

Fair use? If you are challenged over your site, your most robust defense would be that the tests are not copyrightable. Fair use -- which permits the unauthorized use of copyrightable material for specific purposes -- is likely not an issue.