Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewellery and hard-stone carvings, while in the metaphysical world even the smallest piece is imbued with powerful properties that enable the bearer to cross the boundaries between the worlds. Archaeologists are now finding more and more evidence that quartz played an important part in the ritual and burial customs of our Ancestors. In truth, as Dr Meriem Clay-Egerton asserted some forty years ago, the use of quartz in prehistoric stone-working traditions was a worldwide phenomenon. For archaeologists, however, quartz was often misidentified, or ignored. Indeed, well into the 20th-century, quartz artefacts were routinely discarded during excavations. A new study reveals how Stonehenge has stood the test of time so successfully: The quartz crystals that make up the sarsens form an interlocking structure that makes the boulders nearly indestructible.