Earth Sciences 1089G

Geologists' criteria for the estimation of the Earth's age:

• The Chronologers' Quest: The Search for the Age of the Earth (2006) (eBook)
• Subject: Geochronometry (catalogue search)
• Subject: Geological Time (catalogue search)
• Subject: Earth Age (catalogue search)

Birthstones/gemstones term paper:

• Dictionary of Gems and Gemology (2009) (eBook)
• Gems: Their Sources, Descriptions and Identification (2006) (print)
• Gemmology (2005) (print)
• Handbook of Rocks, Minerals, and Gemstones (1993) (print)
• Color Encyclopedia of Gemstones (1987) (print)
• Encyclopedia of Geology (see chapter on Gemstones) (2005) (print)
• U.S. Geological Survey (search for "gemstones") (online)
• Geological Survey of Canada (online)