This Armour system is very complicated, so I assume it would be hard to understand. I will explain each type of Armour, and new armors.

Leather - Leather Armour breaks easier than gold, but it lasts longer because gold is heavy, and brittle. But leather Armour could be combined with 1 iron ingot to make leather studded Armour.

Leather Studded - Leather studded is the same as chainmail, but it has less durability. It is lighter than all other Armours except normal leather, so you can walk/run a bit faster.

Gold - Gold armour is very heavy so you can not run that fast, but it has the 3rd best armour rating (of the normal armours) . If combined with iron it makes iron/gold armour, which is stronger than gold, and also has a better durability. And if combined with leather, makes leather gold studded armour (you can make your own names for these terms) It gives it a bit less armour rating than gold, but more than leather. It's durability is less, but it is lighter.
If gold is combined with diamond, it makes Diamond/gold armour, which is one of the best armours possible, with amazing durability, speed, and armour ratings. This is the armour to go for. If gold is combined with chainmail, then it makes golden chainmail armour, which is the same durability is chainmail, but with a higher armour rating.

Diamond - Diamond is the same in weight as Iron, you can run a bit slower than normal. Its durability would be a bit higher than it already is, but it depends on whats hitting it. If combined with iron, this makes Diamond/iron Armour, which is the best armour possible, you can run normally, and you also have amazing durability (like when you enchant leather to unbreaking 4.) When combined with leather, you get Leather Diamond Studding, you can move quite fast, and you have a armour rating like iron. Its durability is the same as chainmail.

Ruby - This would be the new kind of armour, it has a better armour rating than Diamond, a durability higher than diamond, and you would be able to run faster than normal. It also is easier to enchant with higher enchantment levels. Like if you got ruby boots, and you wanted to enchant them with a good enchantment, you could put in a level 15 enchantment and get: Protection 4, feather falling 3, and fire protection 1. It can not be combined with anything, and much harder to find than diamond.

New armour system - I like the armour system already, but it needs to be more realistic. Whenever you fall on the ground, your boots dont take any damage. And when you have full diamond with fire protection 4 on all, you still die of burning if you fall into lava for 2 seconds. Well not anymore! When you get hit in the upper body, you should take more damage than if you got hit in the leg. And if you got hit in the leg, you should be slower. Its just some minor tweaking that I think would be pretty d*** cool.

If you read the entire thing and like it, please give this a diamond and vote for it on the Minedea challenge, Thanks!
-TerrariaHero