Why do some gemstones glow under ultraviolet light? Discover the science of gemstone fluorescence, electronic excitation, activators, quenching and phosphorescence, with examples from ruby, sapphire and diamond and an explanation of how fluorescence supports professional gemmological identification.
Discover zircon through professional gemmology. Explore its geological formation, exceptional birefringence and dispersion, uranium-related crystal damage, colour mechanisms, heat treatments, inclusions and laboratory identification. Learn why natural zircon is fundamentally different from cubic zirconia.
Discover emerald from a gemmologist’s perspective: how this green variety of beryl forms, how chromium and vanadium create its colour, and how optical properties, inclusions, spectroscopy and trace-element chemistry reveal its identity, treatment and geological history.
Few gemstones attract attention as quickly as a fine red ruby. That attraction can also make ruby one of the more complicated coloured gemstones for consumers to purchase confidently. Two stones that both carry the name “ruby” can differ enormously…
Why can one gemstone show different colours from different directions? Explore the science of pleochroism, dichroism and trichroism, and discover how crystal structure, selective absorption, the dichroscope and cutting orientation influence gemstone colour.
What does eye-clean really mean? Explore gemstone clarity, inclusions, transparency, magnification and durability, and learn why clarity must be evaluated differently across emerald, ruby, sapphire, aquamarine and other coloured gemstones.
Buying a blue sapphire is about more than choosing the deepest blue stone. Lena Hoffmann explains how to evaluate appearance, ask the right questions about treatments and origin, and recognise the importance of reliable disclosure before purchasing.
Gemstone inclusions are more than imperfections. Mineral crystals, fluids, growth structures and healed fissures can preserve evidence of formation, treatment and origin. Discover how gemmologists interpret the microscopic world inside natural gemstones.
Discover emerald from a gemmologist’s perspective: how this green variety of beryl forms, how chromium and vanadium create its colour, and how optical properties, inclusions, spectroscopy and trace-element chemistry reveal its identity, treatment and geological history.
Natural, synthetic and simulant gemstones can look remarkably similar while having fundamentally different origins and properties. Discover how gemmologists distinguish them using growth features, inclusions, optical properties and advanced laboratory testing.
