Libyan Desert Glass Impactite Individual, 178.68g, Golden Yellow-Green Natural Silica Glass

Golden silica glass forged in the Sahara

This 178.68g individual of Libyan Desert Glass presents the characteristic translucent yellow-green coloration that defines this impactite. The specimen preserves natural flow textures frozen at the moment of formation, when temperatures exceeding 1,700°C melted desert sand into lechatelierite glass. The surface shows the sculptural contours typical of specimens weathered free from Saharan dunes over millennia.

Collected in 2024 from the Great Sand Sea strewn field, this piece exhibits the distinctive optical clarity that makes Libyan Desert Glass visually compelling. The golden hue results from trace iron content in the original quartz sand substrate, while the flow patterns document the chaotic mixing of molten material during the impact event.

Structure and features

The specimen displays classic lechatelierite structure throughout. Flow banding visible in transmitted light records the movement of molten silica during the seconds following impact. The surface exhibits natural weathering patterns acquired during its residence in the desert environment, including subtle abrasion marks from wind-driven sand.

Translucency varies across the piece, with some areas approaching transparency while others show slightly opaque zones where gas bubbles became trapped in the cooling glass. These bubbles, typically microscopic to millimeter scale, formed as volatiles escaped from the superheated quartz. The yellow-green coloration remains consistent, indicating uniform chemical composition of the source material.

Scientific context

Libyan Desert Glass formed approximately 29 million years ago during the Late Oligocene when a meteorite or comet impacted the Sahara. The extreme heat and pressure of this collision instantaneously melted the silica-rich sand, creating a natural glass composed of nearly pure silicon dioxide. The strewn field spans roughly 6,500 square kilometers in the Great Sand Sea along the Libya-Egypt border.

Unlike tektites, which are ejected as molten droplets and cool in flight, Libyan Desert Glass represents in-situ melting of target material. The formation requires temperatures between 1,700°C and 1,900°C, achieved only through hypervelocity impact. No impact crater has been definitively identified, though the Kebira structure remains a candidate. Learn About Meteorites to understand the distinction between impactites and other impact-related materials.

Frequently asked questions

Is this material authenticated? Libyan Desert Glass from the Great Sand Sea strewn field is recognized by geologists worldwide. This specimen includes a certificate of authenticity documenting its provenance from Libya. As an impactite rather than a meteorite, it does not appear in the Meteoritical Bulletin, but its identity is confirmed through composition and find location.

What is lechatelierite? Lechatelierite is natural silica glass formed when quartz sand melts at temperatures above 1,700°C and cools rapidly. The name comes from French chemist Henry Louis Le Chatelier. This glass structure differs from crystalline quartz because the silicon and oxygen atoms lack organized arrangement, frozen in the random configuration of a liquid.

Why is Libyan Desert Glass yellow-green? The distinctive coloration comes from trace amounts of iron present in the original desert sand. During the impact event, this iron remained distributed throughout the melt, giving the glass its golden-green hue. Coloration intensity varies between specimens based on iron concentration in the source material.

What is included with this specimen? This specimen weighs 178.68g and includes a certificate of authenticity. No display stand is included.

How old is this glass? Radiometric dating places the formation event at approximately 29 million years ago during the Late Oligocene epoch. The glass has remained in the Sahara since formation, becoming exposed at the surface as wind removed overlying sand deposits.

Collector significance

Libyan Desert Glass occupies a distinctive position among impact materials. Ancient Egyptians valued this glass for carving—a scarab fashioned from this material was found in Tutankhamun's pectoral. Modern collectors seek specimens for their scientific importance and aesthetic appeal. The translucent golden color and natural sculptural forms make each piece visually distinctive.

This 178.68g individual provides substantial size for display while remaining accessible. The weight and dimensions allow observation of flow textures and optical properties without magnification. Collectors building Tektites & Impactites collections often prioritize Libyan Desert Glass for its documented formation mechanism and historical significance. The material's rarity—restricted to a single strewn field in one of Earth's most remote deserts—adds to its appeal among impact glass specialists.