Opal has periwinkle skin and thick, wavy, cream-colored hair. Her hair extends slightly past her knees, and is tied by a pale orange band into a rowdy ponytail, resembling Amethyst's hair, except for her chin-length bangs, which resemble Pearl's. Opal has four arms, and her nose is pointed like Pearl's. Her plump lips are similar to Amethyst's.
Opal sports a blue-green tube top that drapes down to her shins, featuring an accented star at the base. She wore magenta leggings with lavender cuffs and light-gold flat-boots.
Her attire is similar to her previous outfit, but with a sash around her waist, a tank top, and an added neckline to her top. This is due to Pearl's regeneration in "Steven the Sword Fighter." However, the colors are yet to be confirmed, since she appeared in a white and green tint. They are assumed to be the same, with slight differences.
Amethyst and Pearl are extremely powerful when they're willing to work together in the form of Opal. Amethyst's ability to live in the moment plus Pearl's obsessive single-mindedness result in a Fusion that is very balanced. Opal achieves a peace in that balance that Amethyst and Pearl rarely experience on their own. Such peace, in fact, that Opal can sometimes completely forget what she's supposed to be doing (For example, forgetting to retrieve the Heaven Beetle after rescuing Steven).
Perfect balance is very difficult to hold. It doesn't take much to make Opal fall back into Amethyst and Pearl.
Opal's personality is speculated to be a combination of Amethyst's power, along with Pearl's grace and precision. She appears to be more open to Steven's desire to have fun and play, as she sang part of his song back to him.
She is very agile and graceful, being able to stand on the tips of her toes and execute acrobatic reflexes. Opal is also shown to be able to leap considerable distances and "skate" or "glide" across the ground.
Bow and Arrows Proficiency: Opal's weapon is an opalescent longbow that fires arrows made of a light-based energy. The bow is roughly as tall as Opal herself. Due to Opal being a fusion of Amethyst and Pearl, she can summon either Amethyst's whip or Pearl's spear at will. She fuses both weapons together to form her bow. Pearl's spear makes up the limbs of the bow while the lash of Amethyst's whip becomes the string. Her arrows are summoned when the bow is drawn back, and these arrows cause a large explosion which emit a bright light on impact, as well as bearing a striking resemblance to the energy blasts that Pearl's spear is capable of. The arrows are also capable of splitting into several smaller arrows and attacking multiple targets at once. Targets pierced by these arrows have their remaining gems bubbled.
Water-Walking: Opal is able to walk on water, as seen in "Giant Woman", while she fights against the Big Bird. She presumably retains this ability from Pearl. Lion and Lapis Lazuli are also known to be capable of this.
Opal and Garnet are on seemingly good terms and work together well. When she returned with Steven in "Giant Woman," Garnet did not seem surprised and simply asked her if she completed her mission. Later, in "The Return", Opal recognizes Garnet's leadership and awaits her command to fire her arrow/arrows, working together without problems while attempting to destroy the Gem Warship.
As seen in "The Return", she is at least twice as tall as Garnet.
Opal and Stevonnie are the only fusions that have no more than two eyes.
She was the second fusion (after Garnet) to be seen, albeit the first fusion to be introduced as one.
Opal's appearance consists more of Pearl's physical appearance and features.
This also extends to her weapon; Pearl's spear not only makes up the longbow but the arrows are visually similar to the energy blast her spear can emit. Meanwhile, Amethyst's whip merely acts as the bowstring.
Opal is the only Gem with an exclusively ranged weapon. This is most likely due to Pearl's spear having the ability to create multiple energy blasts despite being a melee weapon. She can also throw this spear with impressive speed and accuracy, wielding it with impeccable skill.
Opal is among the most human-looking fusions; only Garnet, Stevonnie, and Rainbow Quartz have more human-like appearances.
It can be inferred that more stable fusions look closer to a humanoid figure. In that case, despite their constant bickering, Pearl and Amethyst must share a deep emotional connection and mutual respect for each other.
Opal was the first fusion whose constituent gems (Amethyst and Pearl) were shown attempting a fusion dance. She was also the first fusion whose dance was unsuccessful.
She, along with Garnet, are the only fusions who have bubbled gemstones on-screen.
When Opal's arrow bubbled the Gem Shards from the Big Bird, her bubbles were colored mint-green.
Opal is one of two fusions who have not been shown forming on-screen. The other is Alexandrite.
She is among the least talkative fusions. Of all the fusions who speak with clarity, she has the fewest lines.
The least talkative is Rainbow Quartz; while she is ostensibly capable of human speech, she has no dialogue at all in her only appearance to date.
Opal will have a new appearance, due to Amethyst's regeneration. This will make her the fusion with the most different outfits, after Garnet.
She and Alexandrite are the only fusion Gems who haven't made their debut in season 2.
She seems to stand on her toes usually.
Opal closely resembles Kali, a Hindu deity, featuring four arms, long hair, and a gemstone lodged on their foreheads.
Additionally, Opal was originally planned to make a manji (a Hindu symbol that resembles a backwards facing swastika, though they are unrelated) with her arms when summoning her weapon, of which Kali is commonly associated with.
She is also similar to the design of Nabooru from The Legend of Zelda: Ocarina of Time; even to the point of having her pointed nose.
She also resembles the Hindu deity Lakshmi, who, like Opal, has four arms. Opal's weaponry also revolves around light, something Lakshmi is closely associated with.
Opal's theme is a style of music called High-Energy Piano Anthem, a type of music invented by Masami Ueda, the composer for the Bayonetta games.
Opal's hair closely resembles Korra's from the Nickelodeon show The Legend of Korra.