Two of the more useful crafting bases in Path of Exile 2 never show up as loot. The Diamond Jewel and the Pearlescent Amulet both have to be made at the Reforging Bench by combining other items, which means you can't farm them directly from enemies no matter how long you grind.
Unlock the Reforging Bench first
Both recipes run through the Reforging Bench, so you need access to it before anything else works. You earn the bench in Act 3 by completing the Treasures of Utzaal side quest. Once it's unlocked, the bench lets you drop three similar items into its slots and merge them into a single new base.
The same bench handles both crafts. The only difference between making a jewel and making an amulet is which three items you feed into it.

How to craft a Diamond Jewel in Path of Exile 2
The Diamond Jewel arrived in the 0.5 update as a non-unique jewel base. That distinction matters, because before this change, every base in the jewel category was a unique item that you couldn't modify. The new Diamond can be rolled and crafted like a normal base.
What makes it valuable is its modifier pool. The Diamond can roll affixes pulled from the Ruby, Sapphire, and Emerald jewels all at once. That lets you stack combinations that weren't possible before, such as two separate defense layers like Armour and Energy Shield sitting alongside Movement Speed and other strong mods, depending on your build.
Step 1: Gather one Ruby, one Sapphire, and one Emerald jewel. The reward caches inside the Trial of the Sekhemas are the most reliable place to farm these jewel bases.
Step 2: Open the Reforging Bench and place all three jewels into the reforge slots.
Step 3: Confirm the reforge. The three jewels convert into a single Diamond Jewel base ready to be modified.
There is also a Time-Lost variant of the Diamond. You produce it using the exact same reforge process, so the steps don't change.

| Diamond Jewel ingredient | Source |
|---|---|
| Ruby jewel | Trial of the Sekhemas reward caches |
| Sapphire jewel | Trial of the Sekhemas reward caches |
| Emerald jewel | Trial of the Sekhemas reward caches |
How to craft a Pearlescent Amulet in Path of Exile 2
The Pearlescent Amulet has a Level 30 requirement and carries the implicit modifier +7-10% to all Elemental Resistances. It's one of the amulet bases built around that elemental resistance implicit, but unlike most of the others, it doesn't drop from enemies. You have to make it yourself.

Step 1: Collect a Lapis Amulet, an Amber Amulet, and a Jade Amulet. These can be any rarity, and they each grant a different attribute. Lapis gives Intelligence, Amber gives Strength, and Jade gives Dexterity.
Step 2: Place all three amulets into the Reforging Bench slots.
Step 3: Reforge them to produce a Pearlescent Amulet.
You can also obtain one from Rog by handing him a Humming Pearl, which skips the reforge entirely.
Unlike jewels, every amulet in the game shares the same modifier pool. That means the elemental resistance implicit is the only thing that truly separates a Pearlescent from any other amulet base. Its rolled mods will look the same as those on a Lapis, Amber, or Jade.

| Pearlescent Amulet ingredient | Attribute granted |
|---|---|
| Lapis Amulet | Intelligence (INT) |
| Amber Amulet | Strength (STR) |
| Jade Amulet | Dexterity (DEX) |
How to confirm the craft worked
Each reforge succeeds the moment the bench replaces your three input items with a single new base in the output slot. For the jewel craft, you'll see a Diamond Jewel where the Ruby, Sapphire, and Emerald used to be. For the amulet craft, the result will read as a Pearlescent Amulet with the +7-10% to all Elemental Resistances implicit listed on it.
If the bench won't complete the reforge, the most common cause is mismatched ingredients. You need the exact trio for each recipe, since any other combination won't produce these bases.
With the Reforging Bench unlocked and the right three items in hand, both bases are quick to put together. Stock up on spare Ruby, Sapphire, and Emerald jewels from Trial of the Sekhemas runs, keep a few cheap Lapis, Amber, and Jade amulets on hand, and you can roll fresh Diamonds and Pearlescents whenever your build calls for them.