While 22K is also used in jewelry, it’s often used to make plain pieces which are only meant to be worn occasionally. That’s because 22K gold is too soft for everyday wear, and gemstones and diamonds are too heavy for such a delicate metal.
On the other hand, 10K gold is very sturdy, so it doesn’t scratch or bend easily. 18K, however, is much more delicate, so you have to be more careful with it. A great middle ground between the two is 14K gold, which is why it is so popular in jewelry. It’s durable, sturdy enough for daily wear, and you get a high percentage of gold in the alloy.