小豆島温泉 里枝の湯
Shodoshima Onsen Rie-no-yu黄
Sulfur
+ Sulfate
Classification
Sodium-Calcium-Magnesium Sulfate spring
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.
Source temperature
19.8°C
Cold mineral
Tonicity
0.48g/kg
Hypotonic
Free CO₂
7.00mg/kg
Low
Radon
15Bq/kg
Low
Highlights
- Sulfur-rich
- Cold mineral
- High silica