Bronze Ingot
Made by smelting a bronze key. Can be used to make a ring/pendant, tools/armor, and a block. They all have unique uses. The ring decreases the experience to repair by 1 per ring. The pendant increases the experience obtained for repair skill by 5%. The armor adds the slowness effect, but has a protection equivalent to obsidian (could be higher). When holding the tools, you also gain slowness, but mines a little faster than diamond with less enchantability. The block can be used on beacons. If it is too op for the recipe to make an ingot, maybe the key can smelt into three nuggets which can then be crafted into an ingot.
Silver Ingot
Made by smelting a silver key. Has the same uses as the bronze ingot with different unique uses. The ring grants haste when mining a hard block (mainly obsidian, 2.5% chance). The pendant grants sharpness 1 when killing a mob in one hit (10% chance, the mob must have at least 20 health to work) The tools have the same durability as iron but mines at the speed of gold, with a little bit less enchantability. The armor glows a little bit in the dark. If that is not possible, then it could be the same as bronze with higher protection and slowness 2. The block glows a little bit and can be used for beacons. Like bronze, the recipe could be for 3 nuggets.
Brass Ingot
It turns out the key isn't made of actual gold! Instead, it is made of brass. Smelting a gold key grants a brass ingot (or 3 nuggets). These are a little bit more powerful than gold. They have the durability of a stone tool, but speeds better than gold and gives slowness 1. The armor has the same durability as gold, but has a strength higher than Valkyrie. The ring gains fire resistance when in fire/lava (5% chance). The pendant also gives fire resistance (2.5% chance) along with the haste effect that the silver ring has (3% chance). The block can be used in beacon bases.
Now that we got the keys covered, lets get on to some more stuff that I think would be cool:
Onyx Pickaxe
Made like any other pickaxe, just using onyx. Mines at the same speed of gold, has the same durability as a spectral tool, but cannot be enchanted. Good for inexperienced players who found onyx.
Freezium
An ore found in the mining world. Freezes the player for 5 seconds (just like the boss snowman) when mined. Drops freezium crystals. Spawns in groups of 1, because the sound would just keep repeating. The crystals can be smelted into ingots, and then used for the block. The block, however, doesn't freeze players and creates snow around it. This can be used for a snow farm. The block can also be placed below a freezer to "superboost" it, meaning that the freezer is three times the speed of a normal freezer.
Fire Crystal
Another ore found in the mining world. Catches the player on fire for 5 seconds. Spawns in groups of 1. Drops fire crystals which are then directly used for the fire crystal block which emits the same brightness of glowstone and creates flame particles. The block can also be placed below a furnace to boost it.
Ender Quartz
Made from 4 nether quartz and 5 ender pearls. Looks like an ender-type nether quartz. Used the same way as nether quartz.
Bronze Fishing Rod
Made with bronze ingots rather than sticks. Has the same durability as any iron tool. This can be useful for anyone who needs a better rod.
Artificial Spawner
Made with 8 silver ingots. Can be used just like my old suggestion, "The Empty Mob Spawner". Basically, you put a spawn egg in, but only lasts for 1000 spawns. When it reaches 1000 spawns, it will become inactive. This can be repaired with essence of undeath, removing 100 spawns from it.
Brass Fishing Rod
This is made with brass ingots rather than sticks. This is just like a normal fishing rod, with a few tweaks. Fishing takes 25% longer, in return of 50% more likeliness of catching a treasure. Enchantability is larger.
Dry Ice
Dropped from freezium ore (25% without fortune/silk touch). Don't know what it would be used for rather than freezer fuel and the block. The block would be just like ice, just a lot more speedy. This will not hurt the player like in real life, that would make no sense. The block breaks into normal dry ice.
Sulfur
Dropped from fire crystal ore (30% without fortune/silk touch). Can be used as a strong furnace fuel (smelts 16 items). Can also be made into a sulfur block, which smelts 160 items. This would be useful for disenchanters. There is also a sulfur torch, which is made with sulfur and a stick. The torch will prevent mobs from spawning in a range of 16x16x16 blocks. (like the chandelier in extra utilities). One more thing: This is not smelly, but could make yellow smoke particles to make it look like it is.
Obsidian Crystals
Made from 2 fire crystals and 2 freezium crystals in an infusement altar. You will obtain 16 obsidian crystals. They are then used to make "Obsidian Glass". This is a very cool looking glass that is blast resistant (I know it isn't very useful, it is just mainly for decoration).
Note: The textures are slightly transparent.
