小豆島温泉 里枝の湯
Shodoshima Onsen Rie-no-yu黄
Sulfur
+ Sulfate
Sodium-Calcium-Magnesium Sulfate spring
Cold mineral source · 20°CSulfur-richCold mineralHigh silica
Composition fingerprint0.5 g/kg dissolved · Hypotonic
Na⁺47
Ca²⁺28
Mg²⁺23
SO₄²⁻68
Cl⁻18
S₂O₃²⁻14
◀ CationsAnions ▶
- Sodium Na⁺
- salt's cation — pairs with chloride to make the water salty.
- Sulfate SO₄²⁻
- "gypsum / Glauber's salt" — vessels and wound healing.
Known good for
- Skin conditionsatopic skin, eczema
- Circulationtired legs
- Aches & jointsstiff shoulders
- Sensitive-skin cautionbroken or dry skin
A cold-mineral spring (source 19.8 °C) at Nōma on Shōdoshima. Mineralization is modest at 0.49 g/kg, but the chemistry blends a sulfate backbone (SO₄ 225 mg/kg) with bound sulfur from thiosulfate — enough total S to fall in the sulfur-spring family. Metasilicic acid sits at a generous 73.9 mg/kg, giving a noticeably smooth feel. Reheated for bathing, as is standard for sub-25 °C sources.