Quartz

Quartz is one of the most abundant and diverse minerals on Earth, second only to feldspar in the Earth's continental crust. It is composed of silicon dioxide (SiO₂) in a continuous framework of SiO₄ silicon–oxygen tetrahedra. Quartz is renowned for its durability, chemical stability, and wide variety of colors and forms, making it a favorite among collectors and scientists alike.

Formation & Geology

Quartz forms in all types of geological environments: igneous, metamorphic, and sedimentary. It is a primary constituent of granite and other felsic igneous rocks. Because it is highly resistant to chemical weathering, quartz persists as grains in soil and sediment long after other minerals have broken down, eventually forming the vast sands of the world's beaches and deserts.

Physical Characteristics

In its purest form, often called 'rock crystal', quartz is colorless and transparent. However, it frequently contains impurities that create a spectacular range of colors. Amethyst (purple), Citrine (yellow), Rose Quartz (pink), and Smoky Quartz (brown/black) are all varieties of the same mineral. Quartz crystals are hexagonal prisms, often terminated by hexagonal pyramids, though they can also occur in massive, distinct habits.

Historical Significance

The name 'quartz' comes from the German word 'Quarz', which is of Slavic origin. Ancient Greeks referred to quartz as 'krystallos' (ice), believing it was water frozen so hard it could never thaw. Throughout history, it has been used for jewelry, carving, and ritual objects. In modern times, its piezoelectric properties—the ability to generate electricity under stress—revolutionized timekeeping (quartz watches) and electronics.