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.