Clojiia is a "hothouse" terrestrial world with a dense atmosphere of nitrogen and sulphur dioxide. The surface is scorching hot, and mainly composed of iron with deposits of gold.
The core of Clojiia is very hot and tectonically active. Volcanic eruptions are common, and the outgassing continues to add to the density of the atmosphere. The largest active volcano has a caldera nearly 100 kilometers in diameter, and its basalt floods have covered an area roughly equivalent to the size of the Earth continent of Australia.