Amber
Amber is fossilized tree resin valued as a gemstone and known since antiquity for producing static electricity when rubbed.
Electrostatics: The study of electric charges at rest and the forces, fields, and potentials they produce. Rubbing amber transfers charge, making it a familiar demonstration of static electricity.
Baltic amber: A major amber variety formed from resin produced by ancient trees in northern Europe. Its abundance and age make it a defining example of amber formation.
Amber jewelry: Ornaments made with amber, often cut, polished, or set in metal. Jewelry is the most visible human use of amber across many cultures.
Thales of Miletus: A Greek philosopher traditionally credited with observing that rubbed amber attracts light objects. The ancient account connects amber's frictional attraction with early natural philosophy.
Triboelectric effect: The transfer of electric charge between materials that come into contact and separate. This effect explains why rubbed amber attracts light objects.
Dominican amber: Amber from the Caribbean island of Hispaniola, often noted for its clarity and fossil inclusions. It shows how a distinct source region yields amber with a different fossil record.
Amber inclusions: Organisms or other materials trapped and preserved within amber. Inclusions can preserve detailed evidence of ancient ecosystems.
Electricity: A set of physical phenomena associated with electric charge, current, and electromagnetic fields. The English word derives through Latin and Greek terms associated with amber.
Static electricity: An imbalance of electric charge on or within a material that is not flowing as a current. Amber can retain the charge produced by friction long enough to attract nearby particles.
Copal: A young, incompletely fossilized plant resin that resembles amber but is generally less geologically mature. Copal distinguishes recent resin deposits from fully fossilized amber.