I used MCreator to create this mod for my server and based some textures off of an old mod called Varied Commodities

Coins

Common

Wood (1PC)
Stone (4PC)
Copper (16PC)

Uncommon

Iron (64PC)
Gold (256PC)
Platinum (1,024PC)

Rare

Amethyst (4096PC)
Sapphire (16,384PC)
Ruby (65,536PC)

Epic

Diamond (262,144PC)
Emerald (1,048,576PC)
Netherite (4,194,304PC)

Some Coins have special abilities:

Wood - You can use this item as fuel
Copper - Stand to close to any conductive blocks with these in your pocket...
Gold - Some times you feel lucky, others...
Amethyst - Now hear me out, Flowers, maybe...
Ruby - Trade XP for blood or blood for XP
Diamond - Harden yourself
Emerald - Villagers love me
Netherite - Planes walking or just unlimited ender pearls

How do you get coins?

You can find them from ores or flowers

How do I store these coins? they take up too much space

Craft and ATM machine

How do I make x coin from y coin

To make the next tier, it requires 4 of the one below it. So 4 Wood coins makes 1 Stone coin, and 1 Stone coin makes 4 Wood coins.

Coin Flower

The Coin Flower is very fragile, Touch it and it might break into coins. However if you find a way to harness it's power without touching it, you can harvest coins from it. So long as it has the nutrients it needs.- -

Mark's Coins