Mie scattering
The source of the river's distinctive turquoise color is not due to a chemical species but to a physical phenomenon known as Mie scattering. Celeste River is fed by two colorless rivers, the Buenavista River and Sour Creek. Buenavista River carries a large concentration of aluminosilicate particles with a small diameter. Sour Creek, as its name implies, has a high acidity due to volcanic activity. When these two streams mix to form Celeste River, the drop in pH causes the aluminosilicate particles to aggregate and enlarge to a diameter of about 566 nm. These suspended particles produce Mie scattering which gives the river a strong turquoise color.