Whitsunday Islands: the pure silica beach

Seventy-four islands scattered in the Great Barrier Reef guard Australia's purest sand beach, composed of over ninety-eight percent silica.

The islands are reached only by boat or seaplane from Hamilton Island or Airlie Beach.

A boat takes one to Whitehaven Beach, seven kilometres of pristine white sand that does not retain heat even under tropical sun thanks to the purity of the silica.

At the northern end, the Hill Inlet viewpoint reveals from above the sinuous patterns that tides and currents trace daily between sand and turquoise water.

Continuing by boat among the nearby coral banks, snorkelling reveals tropical fish and corals among the most intact of the entire barrier reef, protected by their distance from the continental coast.

Towards evening, one returns to Hamilton Island, the archipelago's main tourist hub and the starting point for most expeditions to the other nearby islands.

The sand at Whitehaven, almost free of other minerals beyond silica, is often used by scientists as a reference standard for studying coastal erosion precisely because of its unusually pure composition.

Hill Inlet's patterns change every day with the tides: a photograph taken on two consecutive days rarely shows the same arrangement of sand and water.