The Strangest Volcanic Rock in Victoria: Icelandite

One small hill in central Victoria erupted something no other location in the state ever has—a rare volcanic rock known as icelandite. In a region dominated by basaltic lava flows, this unique eruption broke the rules of Victorian volcanism and left behind a geological mystery. Formed between 8.3 and 5 million years ago, the Spring Hill icelandite tells a story of deep mantle anomalies, crustal interaction, and volcanic chemistry found nowhere else in Australia. This blog dives into what makes this eruption so special, how it happened, and why the rock it produced is the rarest of its kind in Victoria.