Gem-quality pink fluorite from Planggenstock, Switzerland: chemical and physical properties and a comparison with pink fluorites from other localities

For many, fossiliferous tree resin, primarily amber, gained wide visibility to the public in 1993 wh

pinel is a highly valued gemstone, with its color and quality influenced by trace-element chemistry

Malacacheta, located in Minas Gerais, Brazil, is renowned for its alexandrite deposits and com-plex