Chemistry, Properties and Tests of Precious Stones

Before gemology became a formal field, there was this: a meticulous attempt to systematize everything that made stones precious. John Mastin approaches gemstones as both scientist and craftsman, mapping their optical tricks, hardness, and chemical signatures with the care of someone who understands that beauty has a logic. The first sections establish what any serious student needs to know: how light behaves inside a gem, why some stones split into certain cuts, and which tests separate a real ruby from a clever glass paste. The final chapters walk through each family, from the corundums to the quartzes, building a taxonomy of sparkle. Written in an era when gem testing still relied on ingenuity over instrumentation, the book carries a particular charm: you can sense the practitioner leaning close to a stone, squinting through a loupe, working things out by hand. It endures not because its methods are definitive, but because they reveal the foundations everything later was built upon. For collectors, jewellers, and anyone who has ever held a stone up to the light and wondered what they were really looking at, this is where the wondering becomes systematic.