Let’s face it: Time-keeping is nothing new. By 4,000 BC, Ancient Egyptians used stone obelisks to tell the time. Huge pieces of rock, carefully cut and carved, were deposited in common areas and near temples so that people walking by could observe the movements of the shadows and estimate the passage of the sun. Right around the same time, people in the British Isles were constructing Stonehenge, a huge stone circle that measured the passage of the stars above in a calendar of years, months, weeks, and even hours.
Before long, humans across the world found their own ways to mark the passage of time, and the majority of them turned to rocks. As sundials became popular in the east, early travelers in the Americas marked out time on the walls of stone dwellings. Even when clock-making began to grow into the sleeker, more modern science that we know it to be today, rocks played an unintentionally large part in the process. When Galileo designed the first pendulum in 1583, he realized that it required weights; as Dutch and German engineers sat down to craft the first spring-form watches in the 1650s, watches and clocks required glass faces and beautiful adornment.
Then, just as watch-making seemed to have surpassed the days of sundials, obelisks, and water weights, Warren Marrison and J.W. Horton invented a new kind of accurate time-keeping while they were working for Bell Telephone Laboratories in 1927. What was their secret? No surprise here: It was rocks.
To be more precise, the key to the modern watch is actually quartz, also known as silicon dioxide. By using quartz to carefully control an electronic oscillator, Marrison and Horton created a watch that had better precision and longevity than any other mechanical clock up until then. Quartz carries electrical signals and can be bent into very specific shapes, which makes it ideal for long-lasting and accurate time measurement.