The equipment can be upgraded in the smithy. The upgrading will make the equipment more powerful. However, the jewelries and some special equipments cannot be upgraded.
The meteorite is tradable between players, which can be bought only through gold.
The untradable materials just like runestone can be bought through gold or coupon.
When you are upgrading an equipment, there is a certain rate to fail. If you put dark green crystal together into the forging furnace, it can make sure that the equipment will not degrade when the forging fails.
The rate of failure grows with the equipment level increasing.