Quartz
Quartz is one of the most abundant minerals in the Earth's crust, made of crystallized silicon dioxide (SiO₂). With a hardness of 7 on the Mohs scale, it comes in many varieties: colorless rock crystal, purple amethyst, golden citrine, rose and smoky quartz. In lithotherapy, lapidaries have credited it since antiquity as an amplifier and an all-purpose stone, the bedrock of most collections.
A whole family of stones
Behind this single name hides almost your entire collection: amethyst, citrine, rose quartz and smoky quartz are all colored varieties of the same crystal. Pliny the Elder claimed that rock crystal was ice frozen so deeply it could no longer melt, which is the very sense of the Greek krystallos. The image stuck: a stone of clarity, as limpid as spring water.
In your practice
Rock crystal is often the first stone people choose, and one of the easiest to live with: hard, stable, at home in water. Lapidaries credit it with amplifying the intention you place in your other stones. A cluster of quartz also makes a charging bed: rest your tumbled stones on it in the evening, the way you drop your keys when you come home.
Sources
- , Natural History, Book XXXVII (77)
- , Manual of Mineral Science (2007)