PROBLEM TO BE SOLVED: To provide an opal which realizes a color development having a color playing effect and a sufficient brightness, and to raise the maintenance reliability of a shape of the opal.SOLUTION: The spherical opal 2 comprises an aggregate which makes a silica particle 1 a principal component, and has a circle shape or elliptical plane part 2a on a part of the surface, wherein a density of the silica particle 1 in a surface part is larger comparing with a density of the silica particle 1 in a core. The opal power includes at least 50 mass% of the opal 2. The method for manufacturing an opal includes: a dropping process in which a silica particle dispersion is made to drop on a flat plate the surface of which is hydrophobic to be made a droplet; a drying process in which the droplet is dried to be a dried product in which the silica particle 1 is condensed; and separation process which separates the dried product from the flat plate.
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