Gem trading is a new feature in Diablo patch 1.0.3b

America has just received the Patch 1.0.3b for Diablo 3, and now a full list of alterations has just been shown. Trading gems, dyes, crafting materials among other things is one of the major changes within the fresh change.

Also claimed is the gold commodity trading is “coming soon”. For Europe and Asia, the patch will be coming soon - to gamers will hopefully not have too long to wait. A full list of changes is as follows, cited below:

Auction House

The following commodities are now available for trading in the real-money auction house (gold commodity trading is coming soon):

-Gems
-Dyes
-Crafting materials
-Blacksmithing Plans and Jeweler Designs
-Pages of Training

Bug Fixes

The “Bid” and “Buyout” buttons will now be correctly grayed-out in the confirmation window when attempting to purchase an item with insufficient gold

General Bug Fixes

Fixed a bug where leaving a heavily-populated General chat channel would prevent players from rejoining any General chat channel until they logged out and logged back in
Fixed several tooltip-related bugs that were occurring when viewing items with 2 or more sockets in the auction house and profile pages
Fixed a rare crash with tutorials on item pickup

Source