Resources

Whakarewarewa geysers, Rotorua. White silica (SiO₂) sinter deposits are formed as dissolved material is precipitated on cooling.

Champagne Pool, Waiotapu, near Rotorua. Silica sinter (white) also has encrustations of arsenic-rich mineral material (orange) deposited from cooling water. Arsenic is a common pollutant in streams draining thermal areas.