Quartz is an abundant mineral in the Earth's continental crust. It is made up of a continuous framework of SiO₄silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO₂. There are many different varieties of quartz, several of which are semi-precious gemstones. Throughout the world, varieties of quartz have been, since antiquity, the most commonly used minerals in the making of jewelry and hardstone carvings.

Quartz belongs to the trigonal crystal system. The ideal crystal shape is a six-sided prism terminating with six-sided pyramids at each end. In nature quartz crystals are often twinned, distorted, or so intergrown with adjacent crystals of quartz or other minerals as to only show part of this shape, or to lack obvious crystal faces altogether and appear massive. Well-formed crystals typically form in a 'bed' that has unconstrained growth into a void, but because the crystals must be attached at the other end to a matrix, only one termination pyramid is present. There are exceptions as doubly terminated crystals do occur. An occurrence in Herkimer County, New York is noted for these Herkimer diamonds with terminations at both ends. A quartz geode is such a situation where the void is approximately spherical in shape, lined with a bed of crystals pointing inward.

James Daniel May (born 16 January 1963) is an English television presenter, journalist and writer. He is best known for his role as co-presenter of the award-winning motoring program Top Gear alongside Jeremy Clarkson , and Richard Hammond.

On Top Gear, May has the nickname "Captain Slow" for his careful driving style, a love of small underpowered cars and habit of getting lost and distracted while driving. However, in a July 2010 episode of Top Gear he drove a Bugatti Veyron Super Sport, reaching a speed of 417.6 kilometres per hour (259.5 mph). After his attempt the Bugatti test driver Pierre-Henri Raphanel took the car to 430 kilometers per hour (267.5 mph).

May has presented a variety of other programs on themes including science and technology, toys, cars, wine culture, and the plight of manliness in modern times. In addition he has released a variety of DVDs and books with similar themes, and wrote a weekly column for The Daily Telegraph's motoring section.

James May was born in Bristol, one of four children; he has two sisters and a brother. May attended Caerleon Endowed Junior School in Newport, then in Monmouthshire. He spent his teenage years in South Yorkshire where he attended Oakwood Comprehensive School in Rotherham and was a choirboy at Whiston Parish Church. He was also at school with Life On Mars and Ashes to Ashes star Dean Andrews. A keen flautist and pianist, he later studied music at Pendle College, Lancaster University. After graduating, May briefly worked at a hospital in Chelsea as a records officer, and had a short stint in Her Majesty's Civil Service.