One of my pet peeves with dungeon fantasy (D&D, Pathfinder, etc.) is boring treasure. There's nothing I hate to see more in a module than the anemic "the chest holds 1,500 gp and a +1 longsword. For my part, I always try to make sure that there's at least a few pieces of memorable, non-magic-item treasure in any adventure I run. There are few things that I find more validating in running those adventures than when the party debates whether or not they really need the cash they'd get from selling that cool whatever-it-is.

In D&D/Pathfinder terms, these are the nebulous "art items", a huge variety of random, typically non-magical stuff that exists simply to be carted out and sold, rather than anything particularly useful to the average adventurer. I'm going to share a few examples from my games, and hopefully you'll follow up with some of your own, and maybe together we can help out that beleaguered GM out there in desperate need of padding out their treasure hoard. So here we go:

• A gilded and bejeweled human skeleton.
• A full bedroom set crafted from exotic hardwoods, complete with silken bedsheets.
• A masterfully-crafted miniature wire-frame animal constructed from mithral.
• A chess set composed of an ebony- and ivory-tiled game board with pieces constructed of dragon bone and Abyssal basalt.
• A collection of coins from a long-lost kingdom. It is a nearly-complete set, representing all denominations minted by the kingdom, save two. Worth a substantial amount as-is, but could easily triple in value if it was completed.
• A set of ceremonial heavy armor carved entirely from jade backed with spider-silk.
• A planar orrery crafted from precious metals and jewels, small enough to fit in a pocket. It appears remarkably accurate.
• A pair of fine leather boots soled in carefully-treated trollskin, which will never wear out.
• A darkwood carriage, its interior upholstered in dark leather and blood-red velvet.
• A case of vintage ice wines made from grapes that had felt the breath of a white dragon.
• A set of fine crystal tableware that, upon closer inspection, is actually composed of magically-stabilized ice.
• A small, shockingly-realistic clockwork crab.

I've been playing a lot of Chengband (Angband clone) recently and while most treasures there are boring as well (although it's not the point of the game) I do take great delight in finding statues and statuettes within the game.  They show up made from normal materials but a GM could easily add exotic materials much like you have.  And they are simply parts of the game that I drop into the museum until I meet my eventual death.

• Wooden statue of a Horse
• Stone Statuette of a Blue Dragon
• Iron Statuette of a Goblin

Those are, I think, are easily in the game.  But here are some ideas that aren't.

• Agate bas-relief of a Sleeping God.
• Weathered Copper hand, part of a larger statue
• Weeping Pine 1/10 size replica of a gelatinous cube
• A set of 100 flat tiles of quartz with curious unknown runes, although 2 tiles are blank

With magic weapons I try to make them more interesting that just a +1. I usually give the weapon a name (think of Sting, Ice or Glamdring) and often additional powers that might not be obvious at first, but are discovered as the weapon is used.

It doesn't have to be pretty, or even unique, to add atmosphere and nuance to the game.

Inside the hidden closet in the bandit lair you find:
• A set of chainmail missing spots on both shoulders and a large rent in the stomach
• A bent rapier with dwarven runes engraved upon the guard that read 'perfection through perseverence'
• a battered practice dummy with a recognizable face carved on it and the words 'Lord Arsehole' painted on the chest area
• a plaque
  inscription:

  Armour Worn By Harkonnen
  The evil Marquis Harkonnen was defeated in the Battle of
  Grover's Mill by a militia of angry citizens. The Marquis,
  himself, was apparently slain by Roberts of Florin who was
  motivated by the marquis's abduction of Roberts's young bride.

I don't disagree, but I would hesitate to call any of those things "treasure".

I recall a table in the Rules Cyclopedia (think way back) that included in treasure tables things like bottles of perfume or wine, tapestries/rugs, incense, spices, books, furs, and so forth.  Also some interesting descriptions of jewelry that provide some great starting points for treasure items.

In reply to MelJill (msg # 6):

There were a few similar charts in the 1E DMG too. I used them a lot. Fun giving the party a valuable carpet, and watch them try to lug that out of the dungeon.

Necromancer Games also released "The Mother of all Treasure Tables". It's over a hundred pages of treasure piles, ranging from what's in a monster's pocket (10 gp or less), all the way to 50,000 gp treasure trove that takes an entire page to describe. And with no magical items what so ever.

Another book I really like for interesting magical treasure is GURPS' Dungeon Fantasy 8: Treasure. All magical items (and most valuable items) have a number of decorations, since magical items are supposed to be fancy. As an example, here's an item I rolled back in my campaign:
The Couch of Seduction. An old, somewhat garish couch decorated with some clear glass and clay beads. It help put those sitting on it in a romantic mood with an enjoyable pumpkin scent. Mechanically, it cast Bravery on those who sit on it, as well as Purify Air, removing any stench in the immediate area. It has two standard decoration (cheap beads and expensive beads, but in small quantity, adding 50% and 300% to the couch value respectively), and one magical decoration (the pumpkin scent, adding 100% to the value).