The sadanagaïte is a Minéral group of the Amphibole S (Inosilicate), of formula $(K,\; Na)\; Ca\_2\; (Fe^\; \{2+\},\; Mg,\; Al,\; Ti)\; \_5\; (OH)\; \_2\; \backslash ,$.

Its name comes from Japanese professor Ryōichi Sadanaga. Discovered in the island of Honshū (Japan).

Other close minerals

• sadanagaïte potassic , or sadanagaïte-K: transparent. Discovered in the island of Shikoku (Japan);
• sadanagaïte potassic and ferric or ferrisadanagaïte-K: black color. Discovered in the the Ural;
• sadanagaïte potassic and magnesic or magnésiosadanagaïte-K: transparent. Discovered in the island of Shikoku (Japan).