Irgizite is a rare black impact glass from the Zhamanshin impact structure in Kazakhstan. The crater is approximately 14 km across and formed around 0.9 to 1 million years ago, making it one of the younger confirmed impact structures on Earth. Unlike major distal Tektite strewn fields, Irgizites are found inside or close to their source crater, placing them in a distinctive category of proximal, tektite-like impact glass.

Irgizites are typically small, glossy black glass forms, often occurring as droplets, ribbons, sprays, strips, dumbbells, or irregular fragments. Many specimens show twisted, ropy, or splash-like shapes, reflecting rapid melting, movement, and cooling during the impact event. They differ from larger Zhamanshin impact glasses, sometimes called Zhamanshinites, and are especially valued for their compact size, vitreous surface, and tektite-like character.

Studying Irgizite provides valuable insight into crater-associated glass formation, high-temperature impact melting, and the differences between proximal impact glasses and classic Tektites. For collectors, Irgizite offers a scarce and specialised material with direct association to a confirmed crater environment. Each specimen represents a small but dramatic record of natural glass formation during a powerful impact event on Earth.