Lonar impact glass 0,07g – Lonar Crater, Maharashtra, India

This impact glass comes from the surroundings of the Lonar crater in the state of Maharashtra. It formed during a meteorite impact approximately 50 thousand years ago. The impact released an enormous amount of energy, which melted the surrounding rocks within fractions of a second, and part of this molten material was ejected high into the atmosphere. During flight, the droplets of molten rock cooled rapidly and solidified into natural impact glass.

The Lonar crater has a diameter of approximately 1.8 km and a depth of about 150 meters. It is excavated into the basaltic lava flows of the extensive Deccan Traps volcanic province, which formed around 65 million years ago. This makes Lonar exceptionally significant, as it is the best-preserved simple impact crater on Earth formed in continental basaltic rocks.

Impact glasses from Lonar occur in many shapes, ranging from irregular fragments to aerodynamic teardrop-shaped and elongated forms, as well as small spherical particles formed during the flight of the molten material. Most specimens are black to dark brown, often with a matte surface caused by collisions with dust and ash within the cloud of ejected material. A smaller proportion of the specimens have a smooth, glossy surface that formed while traveling outside the main ejecta cloud. Some pieces bear tiny glass spherules or filaments attached to their surface, formed by the adhesion of additional molten droplets during flight.

The chemical composition of the impact glass closely matches the local basaltic rocks. Some samples also contain inclusions of material from sedimentary interlayers that were likewise melted during the impact. Modern microscopic studies have furthermore revealed nanoparticles of metals such as iron, chromium, copper, zinc, silver, and gold, formed by condensation from extremely hot impact vapor. These discoveries confirm that the impact glasses from Lonar represent a unique record of the processes occurring during meteorite impacts under extreme pressures and temperatures.

Thanks to their origin, rarity, and scientific importance, the impact glasses from Lonar rank among the most fascinating natural glasses in the world. They are sought after not only by collectors of meteorites and impactites, but also by geologists and planetary scientists, as they provide valuable information about the processes that have shaped the surface of the Earth and other rocky bodies within the Solar System.