Before even placing the Fragments on the Pillars, you are required to collect and sacrifice 11 different Pearls to the Igneous Altar. If you are wondering what these 11 Pearls are or how to obtain them, here is a detailed guide to the entire process.
How to get Pearls in Fisch
Pearls are obtained as an additional drop reward while fishing for Clams inside Fisch. So, basically, you need to try to hunt for Clams and get Pearls along with them. As of now, there are two types of Clams in Fisch: Clam(Default) and Lava Clams. The for
Clam(Default) & Pearl Drops

The Default or standard Clams are available to Fish at Roslit Bay with a fixed pool on the northern side (-1940, 130, 727). Here, you can try to catch Clam, which is an unusual type of item, in foggy weather conditions using Seaweed as your bait. As you collect it, you will also obtain Pearls. There are a total of 7 different Pearls that you can acquire from the Default Clams. I have mentioned each of them below, along with their rarity.
| Pearl Name | Chance |
|---|---|
| Pearl | 46.99% |
| Gilded Pearl | 19.58% |
| Rose Pearl | 19.58% |
| Mauve Pearl | 7.83% |
| Deep Pearl | 3.92% |
| Aurora Pearl | 1.96% |
| Golden Sea Pearl | 0.16% |
Lava Clam & Pearl Drops

The Lava Clam can be fished at Scoria Reach, also at a Fixed Pool opposite the Ashbrook Town. Equip the Coal Bait and try to fish during the Spring Season to maximize your output. You can collect a total of 4 different types of Pearls, and you can get along with a Lava Clam.
How to Sacrifice the Pearls at the Igneous Altar in Fisch

After collecting all 11 different types of pearls, you can go to the Igneous Altar at GPS (-5325, 138, -1280), where you can give Pearls one by one by standing in front of it and pressing the E button. With each sacrifice, you can see the corresponding light shining under the statue.
What are the best rods to farm Clams in Fisch?
The best rods to farm Clams in Fisch include Verdant Sheer Rod, Evil Pitchfork, No Life Rod, North Pole & more. If you don't have these, you can equip any rod with a decent luck above 60% for the process.
Fisch Pearls FAQs
There are two types of Clams in Fisch: Standard Clam & Lava Clam. The first one is found at Roslit Bay, whereas the second one can be fished at Scoria Reach.
If you manage to collect all 11 Pearls in Fisch, you can sacrifice these to the Igneous Altar to activate it, which is part of the Igneous Rupturer rod.
Since we need to collect all 11 Pearls, it will take 6 to 10 hours if you play on a server with decent luck (above x25). However, nothing is guaranteed, and the entire grind relies heavily on RNG.
For more on Fisch, check out All 12 Fish in Tidefall (100% Bestiary) – Fisch or Fisch Brine Storm Event Guide - Fishes, Event Spawn & more