Spessartine in rhyolites in Colorado and Maine. In Madagascar, spessartines are exploited either in their bedrock or in alluvium. The orange garnets result from sodium-rich pegmatites. Spessartines are found in bedrock in the highlands in the Sahatany valley. Those in alluvium are generally found in southern Madagascar or in the Maevatanana region. Spessartine forms a solid solution series with the garnet species almandine. Well-formed crystals from this series, varying in color from very dark-red to bright yellow-orange, were found in Latinka, Rhodope Mountains, Kardzhali Province, Bulgaria. Spessartine, like the other garnets, always occurs as a blend with other species. Gems with
Diamond (gemstone) the Roman writer Pliny the Elder noted diamond's ornamental uses, as well as its usefulness to engravers because of its hardness. It is however highly doubtful that Pliny actually meant diamonds and it is assumed that in fact several different minerals such as corundum, spinel, or even a mixture with magnetite were all referred to by the word "adamas". Diamonds eventually spread throughout the world, even though India had remained the only major source of the gemstone until the discovery of diamonds in Brazil in 1725. A Chinese work from the 3rd century BC mentions: "Foreigners wear it [diamond] in