Sulphuric

Summary
There is no harsher place in the universe at present than a Sulphur world. The high winds blow rocks around that can do some serious hurt to you. The pools of boiling hot sulphuric acid aren't incredibly healthy either. A complete lack of air just makes it worse. Nothing lives on sulphur worlds. At least, nothing sane.

Dangers
Aside from the local wildlife, Sulphuric worlds have three primary dangers. Hostile weather scours the surface, pools of Sulphuric Acid lurk below, and the atmosphere itself constantly deals acid damage. Several methods exist to lessen these hazards, however.

Crops such as Whitespine and Crystal Shards provide temporary protection against atmospheric acid damage. Whitespine in particular seems to be commonly found on the surface of Sulphuric worlds, making for a risky but potentially viable survival method. Additionally, any piece of Armor which includes acid protection will have the same effect and also provide immunity to Sulphuric Acid as long as it is equipped. Many of the common types of weather, however, appear to have no countermeasures, making surface exploration dangerous even for the best-equipped adventurers.

Codex description
These are probably the harshest environment you'll encounter. Every moment on a sulphur world is lethal. Deadly winds, blowing debris, no oxygen. Lovely. But, they are extremely rich in Sulphur. Not the place for a summer house, though. Yet people keep trying...

Notable Features
You can find on these worlds Cinnabar, Densinium, Sulphur, Lead, Sulphuric Acid, Whitespine.