A beach of ancient travelers
The seven kilometers of dazzlingly white sand at Whitehaven Beach did not form here. The local bedrock of the Whitsunday Islands, the result of volcanic activity that began around 110 million years ago, does not contain the quartz needed to produce such a beach. Instead, this sand is a deposit of ancient sand. Geologists theorize that for millions of years, prevailing sea currents flowing north along the Queensland coast moved the sand. This process, known as longshore drift, picked up quartz-rich sediments weathered from rocks far to the south and transported them northward.
The unique geography of Whitsunday Island, with its headlands and rocks, acted as a trap for this drifting sand. Over immense timescales, as ice ages came and went, sea levels rose and fell dramatically. About 10,000 years ago, at the end of the last glacial period, the sea rose to its current level, creating the beach we see today. During periods when the sand dunes were exposed, freshwater leached out impurities, leaving behind silica of exceptional purity. The beach is composed of 98% to 98.9% pure silica (SiO₂). It is a geological formation, an accumulation of foreign material shaped by geological history.
The science of the squeak
The extreme purity and physical characteristics of the sand give it several unusual properties. The fine, rounded grains are almost entirely uniform in size, a result of the long, abrasive process that wore away weaker minerals and smoothed the hard quartz. This uniformity is the reason for the sand's famous "squeak". When you walk on the dry sand, the near-spherical grains rub against one another, creating a high-frequency vibration that you hear as a squeaking sound. Most beach sand, a mix of rock fragments, coral, and shells, simply grinds silently.
This high silica content also means the sand does not retain heat. Even on scorching days, it remains cool to the touch. The brilliant white color reflects the majority of sunlight, contributing to its low temperature. The sand's fine, powder-like consistency is remarkable, but it can also infiltrate and damage sensitive electronics like cameras and smartphones. A popular but unconfirmed rumor claims the sand is so pure that in the 1970s, NASA considered using it to manufacture the lens for the Hubble Space Telescope.