Quick answer: Pick one up from the purple glint beside Inanis’ New Life flower bed in Mirrorwood Depths (Crimson Forest), or buy one from Quick Hand Zhang for 9,920 Remnant Dust. It pays for an accessory’s second polish.
The Refined Indigo Crystal is an Accessory Polishing Material in Phantom Blade Zero. You need one for each accessory you want to polish a second time. The first one you can reach costs nothing. It sits in the Crimson Forest, a short walk from a bell.
Where to find a Refined Indigo Crystal
The card lists the item under “Accessory Polishing Materials” and reads:
“A pure indigo crystal refined time and again to remove impurities. Ground into a fine, translucent powder, it reveals an accessory’s natural brilliance without excessive embellishment, making it highly prized throughout the Wulin.”
“Required to polish an accessory for the second time.”
Refined Indigo Crystals also turn up in Village of Lu, Pangzhen, Meigu Lake, Mandate Encampment, Mirage Estate, Mount Soulrend and Mountain of Imprisonment.
Where to buy one
Quick Hand Zhang sells Refined Indigo Crystals for 9,920 Remnant Dust each. You’ll find them in his stock at four hideouts:
- Village of Lu
- Pangzhen
- Meigu Lake
- Mirage Estate
His Crimson Forest hideout doesn’t carry it, which makes the Mirrorwood Depths pickup the early way to get one. If you sell a crystal back, you get 4,960 Remnant Dust.
Accessories that need a Refined Indigo Crystal
Of the game’s accessories, 14 can receive a second polish. Each requires one Refined Indigo Crystal and the Remnant Dust listed below. All other accessories have just one polish, which takes a Tainted Crystal Shard. For those 14 accessories, complete the first polish before the second; in all, each requires one shard and one indigo crystal.
| Accessory | Second polish effect | Remnant Dust |
|---|---|---|
 Ancient Armor Fragment | The higher your HP, the greater the damage reduction, up to 40% at full HP. | 7,920 |
 Reflex Device | Increases the timing windows for Parry and Perfect Dodge by 25%. | 7,920 |
 Brass Chest Guard | Reduces Sha-Chi drain rate by 90% while holding [Block] to maintain Guard Stance. | 16,560 |
 Remnant Spark Cage | Triggering a Phantom Edge follow-up attack has a 100% chance to restore 1 Remnant Spark. | 18,720 |
 Crimson Resolve | Landing more than 2 consecutive hits within 1 second increases damage dealt to enemies by 35% for 2 seconds. 4-second cooldown. | 21,600 |
 Formless Divine Mirror | Any [Heavy Attack] attack that hits an enemy builds temporary Remnant Spark. Ranged-type Phantom Edges consume temporary Remnant Spark first and deal 10% more damage. | 21,600 |
 Blessed Jade Pendant | Using Medicine randomly triggers one of five effects: Burning or Poison on yourself and nearby enemies, a Chaos fireball that attacks nearby enemies, a full HP and Sha-Chi restore, or a self-destruct that costs 30% of maximum HP and Sha-Chi. | 28,800 |
 Remnant Spark Cube | Increases the damage of all Phantom Edges by 25%. | 32,736 |
 Guardian Idol | Destruction-type Phantom Edges consume 1 additional Remnant Spark and deal 120% more damage. | 36,720 |
 Crude Radiant Heart | Any [Heavy Attack] attack that hits an enemy builds temporary Remnant Spark. Martial-type Phantom Edges consume temporary Remnant Spark first and deal 7% more damage. | 72,000 |
 Acolyte Whisk | Inflicting Fire, Ice, Lightning, or Poison effects on enemies builds a great amount of Elemental Energy. When fully charged, restores 1 Remnant Spark. | 79,200 |
 Chaos Ring | Chaos Flame inflicts Sha-Chi Burn on enemies and restores 100% of the Sha-Chi they lose. | 79,200 |
 Nuo Mask | Reduces the Remnant Spark cost of Summon-type Phantom Edges by 1. Summons gain Berserk, greatly increasing their damage while active. | 86,400 |
 Nameless Thumb Ring | Increases Sha-Chi Essence buildup rate by 15%. | 122,400 |
With Remnant Dust scarce early on, use your free crystal first on Ancient Armor Fragment or Reflex Device; each costs 7,920 for its second polish.
