Significant pieces of jewelry with various functions, usually magical. Most of these are necklaces, though a few bracelets and rings are scattered throughout.
Crowns
Crown of Wisdom
A white tiara found Annalise was order to find by telepathic message. Its special powers were unknown.
Bracelets
Ancestor Bracelet
A bracelet Alice found in the same woods she and Faith discovered the magic book. Using a website, Alice identified it as one of the rarest in the world. When put on, it can show all mermaids that have existed in the past--in the girls' case, they identified their grandmother and Uncle Bob. Even though only mermaids can find it, the girls decided it needed protection and put it in a box with their other jewelry.
Humanity Bracelet
A silver bracelet given to Cleo by her grandmother. It "contained her human life"; if she touched water while wearing it, she wouldn't transform into a mermaid.
Talie Kresh Bracelet
A bracelet found by Serena in her playhouse. It has the initials "TK" on it, and was accompanied by a note explaining that it was from a shapeshifter named Talie Kresh. When Serena accidentally got wet while wearing the bracelet, it knocked them both out. They woke up on an unknown beach, Aly tied to a small tree. How much of this was the bracelet's doing, and how much Talie's, was unclear.
Triton's Bracelet
A silver bracelet with a small pendant, which Angela found in a box in her room. A note told her that it was from Triton, and to put it on and see what happened. Nothing did.
Earrings
Homing Earrings
A set of earrings given to April and Aria by "Them," to help track down Hope and Ky. They matched the necklaces those two girls had discovered, and would glow when brought near them.
Lockets
Lockets
Two lockets found by Ali and Phoebe in a box of old photos and documents. They could open, but were empty. The girls decided to keep them, since they were pretty.
Lola's Locket
A locket containing pictures of Lola and Chloe. After the theft and return of her shell (and powers), Lola was instructed to transfer her powers from the shell into the necklace, to prevent them from being lost so easily again.
Power-Holding Locket
A locket given to Marlowe by her sister Talie Kresh, which was meant to steal the powers of the other mermaids. Talie later took it back and used it to take Marlowe and Aly's powers.
Replica Lockets
Original locket.
These are lockets based on those belonging to the three mermaids of H2O: Just Add Water. They are silver and oval, each with a small gemstone in a different color, with a wave pattern on the back. They are real lockets, with space for photos or notes inside.
Bella discovered one such locket in the woods, along with a note revealing that its original owner, Mera, was looking out for them. As it turned out, this locket could grant the wishes of the holder.
One by one, Nikki, Melissa and Selena found their versions of these lockets--at the bottom of a lake, in a backpack pocket, and at the bottom of a slide. According to their book, the first triggered the appearance of the others. The lockets would make eclipses "more natural," meaning more influential, but returning any of the lockets to the lake would cause the mermaid to involuntarily transform into water permanently, and her companions to lose their powers and become temporarily paraplegic.
Water Mermaid
A silvery-gold locket which Alexa found while swimming. It contained a note saying only "Water Mermaid," and it made her powers act up--she started getting thrown around by, apparently, air.
Pendants
Starfish Necklace
A beautiful starfish pendant covered in gems, it was given to Paige by her grandmother, Cora, in A Mermaid's Journey. In the past, Joella stole the necklace from Cora's mother when she was sleeping. Cora attempted to convince her that the necklace was too powerful and strong, but Joella wouldn't listen and went to find the Secret Door. Cora fought with her over it, and ended up as the winner, but was sent through the door with it. Since then, Joella plotted revenge on Cora. Years later, when Joella (going under the alias "Morgan") found Paige with the necklace, she tricked her into giving it to her (causing Paige to lose her color). After Desiree came to Siren Springs and went to find Paige, Joella said that she would never let them have the necklace. Despite this, Joella did give it to Paige, but it turned out that she planned to follow both her and Desiree through the door and get revenge on Cora. When her plan worked, Joella confronted Cora about leaving her in Siren Springs, took the necklace from Paige, and broke it. However, a younger Cora appeared and gave the (now fixed) necklace back to Paige.
Cave Necklaces
Three necklaces found by Hailey, Brooklyn and Merlena in the cave where they transformed. Unlike other similar necklaces, they do not match--Brooklyn's in particular, being a gold locket with a key and a heart pendant while the others' are single silver pendants--and it is unclear if they have any magical properties.
Dream Necklace
A pink teardrop-shaped pendant which belonged to Reeva. She fell asleep while wearing it and had a bizarre dream that she guessed was a warning of the future.
Faith's Pendant
Jackie discovered this pendant while searching with Selena and Emily at a destroyed house location. Attached was a picture of Faith's grandmother, and the girls reasoned that the woman must have meant to give it to Faith.
Fire and Ice
Isabella and Macy discovered two necklaces, one red and one blue, while swimming. They immediately linked them to their respective superpowers--fire and ice.
Four Mermaid Necklaces
Four mermaid-shaped necklaces found in a box at the bottom of a pool, which threw Bree, Claire, Skyler and Lauren's powers out of whack and left them still in their tails even after they dried off.
Glowing Crystal
A large pink crystal which Alexa found while swimming. It glowed and knocked her down for no apparent reason, but she decided to keep it anyway.
Glowing Pendant
A semitransparent stone wrapped in silver wire, on a black cord, which first manifested in Sophora's dream--she was trying to protect it from someone. When she woke up, the necklace was tied to the ladder of her bunkbed. When Jordan entered the room and picked it up, it began to glow. Putting it on, Jordan popped a tail immediately.
Mermaid Charm
A mermaid pendant from Talie Kresh, which the girls found on a windowsill. While holding it, Aly got wet and transformed into a mermaid, only to be immediately transported to a cave, where she was captured by a cloaked stranger (most likely Talie Kresh).
Necklace and Note
A heart-shaped necklace in an unnamed, upcoming show by cuteautumn74. Most likely it will be the catalyst in transforming the protagonist into a mermaid.
Overdose Fishyness
A pink heart-shaped crystal pendant on a pink ribbon. Aeryn found it while swimming and decided to keep it. It made her act bubbly, crave sardines, and her tail last even after she was dry. Kathy had to reverse it with a potion.
Power Storage Necklaces
Two necklaces which drew Piper and Alice outside and forced the girls to put them on, then wouldn't come off when they tried. Both were heart-shaped pendants; Piper's was red, Alice's purple. They felt their powers draining into the necklaces, and decided they were taking whatever their bodies couldn't handle. Since afterwards the two girls were perfectly capable of using their powers, this guess seems to be accurate.
Necklace of Beauty
A silver chain necklace with a pendant and unidentified magical powers, which Annalise found in the bushes during her search for the "five magical things."
The Ocean's Gifts
Two silver pendants with blue teardrop-shaped gems. Hope found hers dangling from a bush; Ky tripped over hers on the beach.
The Mermaid's Treasure
Two necklaces described in the book Erica and Jane found at Aqua Falls, later given to them by a clerk at a shop. He was the brother of Haley Little, another mermaid who'd been discovered.
Wishing Necklace
A necklace which appeared around Kristie's neck when she read a note telling her about a wish she could make. She used her wish to ask for a day of being fully human again, which she promptly received. Unfortunately, the necklace was apparently very literal-minded; her half-sincere wish to be fully human was also granted.
This may be the same necklace Kristie wished on to become a mermaid, though it isn't clear.
Turtle Pearl
A necklace which Ashley found in her bag after coming home from the beach. It was a pearl pendant on a silver chain, with a turtle on it. Putting it on, Ashley fell down. Presumably this turned her into a mermaid, though the effect was not immediately apparent.
Teleportation Bubble Wand
A pale green bubble wand and tube pendant on a white ribbon. Natasha dreamed about it, and then discovered a scavenger hunt that led her to it. When she tried to use the bubble wand, it transported her to a hot tub, and then back to the park where she'd found it.
Reacting Pendants
Two squarish gemstones wound in silver wire, one red and one blue. Reeva and Ashley found them while tidying up their room. When put together, the two stones began to react to each other by shaking. After the girls decided that this meant they were magical, both popped tails, and Ashley's was no longer black, but pink.
Replica Crystals
Blue, oddly-cut crystal pendants worn on black cords, based on the set of necklaces that were introduced in the third season of H2O: Just Add Water.
Rikki and Emma found theirs in the caves they first transformed into mermaids, caught in the rocks or attached to the walls, and took them. Any powers the necklaces possessed were unclear; once they made the girls' powers "act up" in an unclear way, but the problem disappeared on its own.
Safety Necklace
A necklace which rendered its wearer temporarily intangible in order to protect him or her. Annalise used one, not knowing what it was, and was protected from what appeared to be a ninja.
Other Necklaces
Gem Chain
A small, transparent crystal on a silver chain. Siara saw it in her mind during a trip inside her own consciousness. Soon after, it was sent to her by someone called Nunya, who was aware of what she'd seen. The note accompanying the necklace told her that the necklace would make it easier to enter her own mind by preventing side effects like unconsciousness and headaches, and keep her focused while she did it.
Possessed Shell Necklaces
While checking her mail, Emma discovered a newspaper article about magical shell necklaces in the ocean. She and Rikki went looking and found them, putting them on. Rikki discovered a note in a bottle, telling her that the necklaces were powerful but dangerous, and when Emma started acting strangely, Rikki threw hers away. She managed to get Emma's off after a struggle, and she went back to normal immediately, with no memory of what had happened. Afterwards she developed a fever, though it wasn't clear if it was connected to the necklaces.
Siren Pendant
A white stone on a black cord, which Emily found in the woods. While wearing it, she discovered that she couldn't pop a tail, and so threw it into the ocean. Later, a note told her she'd been lucky to get rid of it when she did; it could have turned her into a Siren or made her lose her tail permanently.
Rings
Crystal Finder
A plain ring enscribed with the words "the ocean and the moon meet as one in the lunar starburst." It took Kathy and Aeryn on a scavenger hunt for crystals, and teleported them wherever they wanted for the search.
Cursed Ring
A ring which, when put on by Kristina, released an evil spirit.
Evil-Repelling Ring
A plain metal ring which belonged to Alicia, the princess of the undersea world, given to her by her mother. It was called one of the most powerful rings in the seven seas. It was used to control all "bad mermaids." When Lucy, a bad mermaid incognito, stole it on the orders of her mysterious boss, Alicia began turning into a bad mermaid herself--trading places with the worst of the bad mermaids as punishment for losing it. Within five days of losing the ring (or possibly the arrival of Halloween) the transformation would be complete.
Hair Clips
Mermaid Gems
Various hair clips, created by the Sea Creature Shell. When besties Layla and Trinity put them on turn into mermaids when touching water