Hornblende | A soil type described by Tom Stevenson (2011) as ‘a silicate of iron, aluminium, calcium, and magnesium, it constitutes the main mineral found in basalt and is a major component of granite and gneiss.’

Bibliography

Tom Stevenson (2011) The Sotheby’s Wine Encyclopedia 5th Edition by Tom Stevenson (Dorling Kindersley, 2011), p.17-19.