The invention includes methods of forming regions of differing composition over a substrate. A first material having a pattern of at least one substantially amorphous region and at least one substantially crystalline region is provided over the substrate. The at least one substantially amorphous region of the first material is replaced with a second material, while the at least one substantially crystalline region is not replaced. The invention also includes a circuit construction comprising an electrically conductive material extending within openings in a substantially crystalline electrically insulative material, and in which the electrically conductive material corresponds to quantum dots.