See PowerPyx's chapter by chapter treasure walkthrough here.
There are 30 different Jade Carving treasures and they are found between the chapters 20 and 27. If you have played the previous uncharted games you will know what these are. They are flashing objects which are on the floor, you simply go up to them and wait until the hand icon appears on the touch screen. Simply press that to pick up the treasure then it will show you the page with how many you have picked up. Most of them are in plain view and you will see them shining, the others you need to go down different paths. You can check you progress by pressing then looking on Nate's Journal. The trophy will unlock after picking up the 30th one.