Sand & geology
Te Puia / Hot Water Beach
feldspar-rich (plutonic/crystalline terrane)
What's in the sand
Hot Water Beach's sand is iron-rich titanomagnetite eroded from Coromandel's andesitic volcanoes. Geothermal water seeps up through the black sand at low tide, letting visitors dig private hot pools — a rare intersection of sand geology and active geothermal plumbing.
References: source 1
Predicted regional composition
Q-F-L (quartz, feldspar, lithic) fractions sampled from the GloPrSM global sand model at this beach's location.
F 73%
L 24%
GloPrSM v1.0.0 (IJ_QFL). GloPrSM is calibrated on modern river sand; beach sand in the same watershed is a reasonable proxy but not identical.
Got a close-up photo of the sand here?
Take a picture with a coin for scale and send it over. We're building a global grain-photo library and this beach isn't in it yet.
Te Puia / Hot Water Beach-36.8804, 175.8207