In my question Is this revision of the level 2 Transmutation Wizard feature balanced? [Version 2], I intended for "stone" to exclude glass, but I now realize that not everyone reading that has the same interpretation, especially as someone has already given an answer based on glass being included in stone. Would it be appropriate to edit "but not a gemstone" to "but not glass or a gemstone"?
Don't alter the question in a way that invalidates answers
When you alter your question, you have to do it in a way that respects the answerer's efforts. See This Meta.
A correction that clarifies something is generally ok, but a correction that alters the evaluation tremendously - such as removing a feature or lessening its latitude after you had been made aware of it - would violate the homebrew review guidelines, Heading 2: Iterate in follow-up questions, not by editing the same question.
Remember the fix for the next iteration
Maybe cutting out glass is not the only fix you want to do for Revision 3.