Dr. Gladenkov, a Russian geologist, is working on an island in east Russia called Sakhalin. He has taken some American geologists to understand the geology of the island. Buried in weathered rock you can find very pale blue mineral crystals. He calls the mineral glenonite, but none of the American geologists ever heard of such a mineral. It scratches easily with the steel knife, but is harder than a fingernail. Its crystalline structure resembles calcite, another common mineral. However, when you drop some HCl acid on the specimen is does not fizz. So it is not related chemically to calcite.

When the American geologists return home, they research the mineral. They find out that glenonite is rare, and is formed in cold water. The mineral found on Sakhalin was indeed glenonite.