In Tears of the Kingdom, there are some pieces of armor that have effects. These effects can protect Link from harsh weather conditions, increase his attack power, and more. Three pieces of armor that form a Set may generate a Set Bonus. Then there are accessories that are not part of a Set, but they still have their own unique effect.
The 
Opal Earrings is an accessory that players can buy from an armor store somewhere in Hyrule. While they may not get much use in the last stretch of the campaign, they're good to have in areas that require a lot of swimming. Like the other jewelry in Tears of the Kingdom, players will be expected to pay a hefty sum if they want to add the Opal Earrings to their inventory.
Opal Earrings Location
The Opal Earrings are available at the Starlight Memories jewelry store (-3792, 2903, 0043) in Gerudo Town (-3875, -2864, 0043). If this is the player's first time going to Gerudo Town, then the Starlight Memories clerk will be in the Gerudo Town Shelter. However, she won't stock the Opal Earrings until players have completed the "Riju of Gerudo Town" main quest.
The Opal Earrings cost 700 Rupees and has a defense of 3. Wearing them will increase Link's Swim Speed. If players find themselves short on Rupees, they can sell rare ore (ie: 
Ruby, 
Sapphire, 
Diamond) or cooked meals. One diamond ore will go for 500 Rupees when sold to a merchant. Given the rarity of diamonds, it may be better for players to sell about 7 Rubies, as one hunk of Ruby will fetch 110 Rupees. They're also more common than their Sapphire counterpart which sells more, but is arguably rarer.
Rare ore can be farmed from Rare Ore Deposits. These can be found in caves, such as the ones in the Eldin Region (near YunoboCo and Goron City). Players can identify Rare Ore Deposits by their gold ore/sparkles. Rare Ore Deposits can drop any gem (except 
Luminous Stone) and 
Flint. Topaz is more common than Rubies, which are more common than Sapphires and Diamonds.
What to Do with Opal Earrings
Opal Earrings can be upgraded just like the other jewelry accessories from Starlight Memories. Upgrading these will require Opals and Flint. Fortunately, Opals are one of the more common gems (along with 
Amber), and they can be farmed from regular Ore Deposits. Thus, it shouldn't be too difficult to have all the Opal required for the upgrades.
If players haven't done so, they'll want to do the side adventure "Serenade to a Great Fairy," which is part of the "Potential Princess Sightings!" side adventure. This is unlocked by speaking to Traysi at the Lucky Clover Gazette, which is located right before the bridge leading to Rito Village. They'll also need a towing harness for their horse. Players can get this for 3 Pony Points, which are earned by speaking to the stablehead on a first visit, registering horses, or doing side quests from certain NPCs who work at the stables.
Great Fairies are required for upgrading armor. To upgrade armor to the maximum level (4-stars), players will need to do all the "Serenade to a Great Fairy" side quests. Upgrading requires materials and, exclusive to TotK, Rupees.
Here are the Opal Earrings upgrades:
|
Level |
Defense |
Materials Required |
Price |
|---|---|---|---|
|
★ |
5 |
|
10 Rupees |
|
★★ |
8 |
|
50 Rupees |
|
★★★ |
12 |
|
200 Rupees |
|
★★★★ |
20 |
|
500 Rupees |
Best Armor Combinations for Opal Earrings
Since the Opal Earrings give a 
Swim Speed Up bonus, they can be paired with other armor that increases Swim Speed. This means the 
Zora Armor and the 
Zora Greaves. However, since it's fairly simple to get the Zora Helm, the Opal Earrings may be better off paired with another armor set. Furthermore, wearing Opal Earrings + Zora Armor/Zora Greaves won't generate the Zora Armor's Set Bonus. Wearing a complete level-2 Zora Set (with the 
Zora Helm instead of Opal Earrings) will decrease the usage of Link's stamina when dashing in water. The Opal Earrings and Zora Helm also have the same defense at max level.
Instead, players can wear Opal Earrings with stronger armor such as the 
Champion's Leathers and a 28-defense trousers (ex: 
Trousers of the Wild). Since the Opal Earrings' potential is only brought out when swimming, it's likely that players won't equip them unless they're fishing.
The Legend of Zelda: Tears of the Kingdom is available for Nintendo Switch.