James Tennant (mineralogist)

James Tennant
Diamond copy of the famous Koh-i-Noor in its current cut, which was supervised by Tennant
Born	(1808-02-08)8 February 1808 Upton, Nottinghamshire, England
Died	23 February 1881(1881-02-23) (aged 73) London, England
Residence	London
Citizenship	British
Scientific career
Fields	Mineralogy
Institutions	King's College London, Geological Society, RMA

James Tennant (8 February 1808 – 23 February 1881) was an English mineralogist, the master of the Worshipful Company of Turners and mineralogist to Queen Victoria.

Tennant was born on 8 February 1808 at Upton, near Southwell, Nottinghamshire. He was the third child in a family of twelve. His father, John Tennant, was an officer in the Her Majesty's Customs and Excise; his mother, Eleanor Kitchen, came from a family of yeomen resident at Upton for more than two centuries. His parents later moved to Derby, and Tennant attended a school in Mansfield, Nottinghamshire.

In October 1824, Tennant was apprenticed to John Mawe, a dealer in minerals at 149 Strand in London. After Mawe's death in 1829, Tennant managed the business with Mawe's widow, Sarah Mawe, who became known as "Mineralogist to Her Majesty". He purchased Sarah's share of the business on her retirement in 1840.

Tennant attended classes at a mechanics' institute and the lectures of Michael Faraday at the Royal Institution in London. In 1838, on Faraday's recommendation, Tennant was appointed teacher of geological mineralogy at King's College London, later a professor. In 1853 the professorship of geology was added, but he resigned that post in 1869, retaining the other till his death. From 1850 to 1867, Tennant was also a lecturer on geology and mineralogy at the Royal Military Academy, Woolwich. Tennant had an excellent practical knowledge of minerals; when diamonds were first found in South Africa, Tennant verified that they were indeed genuine.