Why does Florida beach sand squeak? Squeaking (sometimes called whistling) sand happens where sand is mostly quartz, very well rounded and highly spherical, according to Scientific American. The frequency and amplitude are related to the grain size and surface texture.

The "squeaking" or "singing" sand in Destin, Florida, is a result of its unique geological composition. The sand is nearly 100% pure white quartz, washed down from the Appalachian Mountains over millions of years. Because the grains are extremely fine, highly polished, and nearly perfectly spherical, they create a specific type of friction when compressed. When you walk on the dry sand, the grains rub against one another; the lack of impurities or jagged edges allows them to "slip" and vibrate at a frequency that produces a high-pitched squeak. For the sound to be audible, the sand must be very clean and dry; moisture or organic debris can "cushion" the grains and mute the effect. This rare phenomenon is a hallmark of the Emerald Coast and is only found in a few places globally where quartz purity is this high.