Noun : They locked their valuables in the hotel safe.    From Dictionary.com. 

They hold that there is such a thing as objective valuableness; namely, that which a rational person, acting consistently and within the confines of the facts, would value.    From Wordnik.com.  [Archive 2005-06-01] Reference

The valuableness of it; it was an image of gold, not all gold surely; rich as he was, it is probable that he could not afford that, but overlaid with gold.    From Wordnik.com.  [Commentary on the Whole Bible Volume IV (Isaiah to Malachi)] Reference

Here was a youth, with the qualities of potential great valuableness, and the wise editor, as soon as this appeared, gave him his chance by calling him off the fields of taxation and currency and assigning him to topics plucked alive from the day's news.    From Wordnik.com.  [Queed] Reference

Why, Sir, there wan't a picture or a piece of furniture or a statuary in that old home that wan't only seasoned with age, but had a store of valuableness to it besides, and you passive and peaceable, taking the news all quiet as if it had been nothing but a fence rail burnt up, and telling me to my face, and me a-bustin 'out with damnation from every pore, that you had heard of the fire, that Mr. Enroughty had reported the burning of Turkey Island yesterday!.    From Wordnik.com.  [Documenting the American South: The Southern Experience in 19-th Century America] Reference