Particles of aluminum salt hydroxide containing an organic acid anion represented by the general formula (1): Ma[Al1-xM'x]bAzBy(OH)n.mH2O (1) [wherein M represents at least one cation selected from the group consisting of Na<+>, K<+>, NH<4+> and H3O<+>, M' represents at least one metal cation selected from the group consisting of Cu<2+>, Zn<2+>, Ni<2+>, Sn<4+>, Zr<4+>, Fe<2+>, Fe<3+ >and Ti<4+>, A represents at least one organic acid anion, B represents at least one inorganic acid anion, and a, b, m, n, x, y and z satisfy 0.7 <= a <= 1.35, 2.7 <= b <= 3.3, 0 <= m <= 5, 4 <= n <= 7, 0 <= x <= 0.6, 1.7 <= y <= 2.4, and 0.001 <= z <= 0.5]. The above particles have the form of a particle, one pair, a rectangular parallelepiped, a disk (a go stone), a hexagonal plate, a rice grain or a cylinder, and have a uniform particle diameter. |