*Aqua regia* (Latin: *Royal Water*) is one of the strongest acids known in Chemistry, and is capable of dissolving gold and platinum.

My copy of the *Oxford* science dictionary goes on to say (under the entry: Aqua regia) that metallic silver does **not** dissolve in aqua regia. It does not  mention any *other* examples of aqua regia-resistant metals. Further down, it mentions that silver's invulnerability to aqua regia is due to the formation of a protective silver chloride coating on the metal, which serves to protect the metal from further decomposition. 

However, this Wikipedia article claims:

>  ...aqua regia does not dissolve or *corrode* silver...

This, I find contradictory to the dictionary's "formation of silver chloride" claim.

So,

**1) What metals (elemental, forget alloys) are neither attacked by nor dissolved in (freshly prepared) aqua regia?**

**2) What makes those metals that don't dissolve or corrode in aqua regia so impervious to the acid?**

**3) Does silver metal actually develop a silver chloride layer on exposure to aqua regia? If so, would that mean the Wikipedia article is incorrect?**