Alexandrite is a massive fusion with bright-magenta skin and six arms. Her eyes are covered by a dark-indigo visor. Instead of a third eye, like Garnet has, she has an alexandrite gemstone, representing the location of Pearl's gemstone, with three dark-indigo oval-shaped lenses surrounding it. Alexandrite's primary face has a structure similar to Pearl's and plump lips like Amethyst and Garnet. This face functions as a mask, covering a second monstrous mouth that has sharp teeth and a long tongue. Both mouths are capable of speech.
Alexandrite's thick, mint green hair is a collision of all the Crystal Gems' hairstyles. The length and wildness of her hair resembles Amethyst's, the top tuft of her hair is styled to a point to resemble Pearl's, the fullness of her hair resembles Ruby's, and the color resembles Sapphire's.
Alexandrite's attire was a combination of the Crystal Gems' clothing: The teal bodysuit with a four-pointed star cutout on each knee resemble Amethyst's, the flats and large, dark-mauve shoulder plates resemble Garnet's, and the dark pink belt resembles Pearl's. The gloves on each pair of arms were the skin tone of her three constituent Gems (Lilac for Amethyst, magenta for Garnet, and aqua for Pearl).
In "Super Watermelon Island", Alexandrite's attire underwent changes due to Garnet and Amethyst's regenerations in "Jail Break" and "Reformed" respectively. Her lowest arms are now located on her waist, featuring gloves that cut off at her elbows instead of covering the entirety of the two arms. She now wears a dark teal leotard with dark mauve and light blue shoulder pads, similar to that of Garnet; and an enlarged red-violet red sash similar to that of Sardonyx. Her leggings are a medium purple with lilac four-pointed star cutouts, resembling Amethyst's.
After Amethyst's regeneration in "Crack the Whip", Alexandrite's attire changes once again in her appearance in "I Am My Mom". The color of her shoulder pads and collar switch colors to be dark indigo and mint green respectively, with the collar having a slight tear on one end. Her legging cutouts are now dark teal.
Alexandrite starts off cold, somewhat distant, intense, and sloppy. As the fusion slowly starts to fail, the Crystal Gems' individual personalities become more prominent, showing Pearl's fear of food, Amethyst's hunger and argumentative personality, and Garnet's social awkwardness, leadership, and control of situations.
During "Fusion Cuisine", she is not shown to have her own personality, but rather three separate personalities, each one being that of Garnet, Amethyst, and Pearl. These personalities can exist at the same time and come into conflict with each other, causing Alexandrite to defuse.
As shown in "Super Watermelon Island", she is able to keep herself together when in serious situations. She is seen to be a ferocious fighter, roaring in a bestial-like manner before charging at her enemy. However, she offers to settle things peacefully before the battle, reminding her enemy that they don't have to fight.
After an inappropriate phone conversation between Dr. Maheswaran and Garnet (who pretends to be Steven's mom), Connie's parents wish to meet Steven's parents for dinner. While Steven has a dad, he has three "moms" and he doesn't wish to leave any of them out.
Steven comes up with the idea of fusing the other three Crystal Gems into one Gem that can represent his mom in his nuclear family. After some initial hesitation, they agree to go through with it. Fused together as the enormous Alexandrite, the Gems stomp to their dinner, where the Maheswarans are impatiently waiting. Greg and Steven have trouble fabricating answers to all of the Maheswarans's questions. Once the food is served, Alexandrite has an internal struggle between the Gems to eat or not eat. They fall out of sync and defuse, surprising Connie's parents.
Alexandrite then shows up for a final time when the Gems fuse off-screen in order to track down the runaway Steven and Connie. She is last seen chasing down and picking up the bus the two were riding out of Beach City.
Garnet, Amethyst, and Pearl form Alexandrite in order to fight Malachite on Mask Island. However, Alexandrite initially tries to reason with the freed fusion before Malachite decides to fight instead. Seeing as they can't reason with the fusion, Alexandrite roars and soon clashes with Malachite.
While initially struggling to fight Malachite, to the point where the fusion encases her in a block of ice, the Watermelon Stevens distract the unstable fusion long enough for Alexandrite to gain the upper-hand in their battle and finally defeat her, using Opal's bow to land the finishing blow. Upon catching the falling Jasper and Lapis Lazuli and reaching the shore, she immediately defuses out of exhaustion.
Garnet, Amethyst, and Pearl fuse in an attempt to stop Aquamarine from launching her ship and taking its passengers, Steven and his friends from Beach City, to Homeworld. Alexandrite, who is holding down the ship, lowers it and Steven tells the others to jump into the water below them, which most of them, save for Lars and Steven himself, succeed in doing. However, Aquamarine manages to freeze all her opponents, including Alexandrite, with the help of her wand. When Steven finally decides to turn himself in to Homeworld in his friends' stead, identifying himself as Rose Quartz, Aquamarine releases the humans as well as Alexandrite. This causes the Crystal Gems to unfuse.
Presumably, Alexandrite possesses standard Gem abilities and traits.
Alexandrite has incredible amounts of physical strength and stamina; her long legs allows her to cover a lot of ground quickly. She uses her sheer strength and size to lift weighted objects, like a bus. Garnet describes her as "an incredible force on the battlefield", making clear Alexandrite is indeed a formidable warrior, capable of anything as long she keeps a singular goal in mind.
Weapon Proficiency: As a fusion of multiple Gems, Alexandrite is skilled in wielding a variety of weapons, such as Opal's bow, Sugilite's flail, Sardonyx's war hammer, and the base weapons of the Gems she is composed of.
Energy Bow Proficiency
War Hammer Proficiency
Anatomy Manipulation: Like Sardonyx, Alexandrite has been shown to have "doll joints", body segments that have full rotation independent of the rest of her body. She is seen spinning her upper body above her sash while attacking Malachite with Sardonyx's war hammer without impeding her lower body movement.
Fire Breathing: Alexandrite is able to create a plume of fire from her lower mouth.
It is said that the stone was named after the Russian emperor, Alexander II (1818 - 1881), but was discovered by a French mineralist called Nils Gustaf Nordenskiöld (1792 - 1866).
When Nordenskiöld first discovered alexandrite in 1834, it was initially thought to be an emerald because it was discovered in emerald mines located in Russia's Ural region, near the Tokovaya River. The specimen was later identified as a chromium bearing, color-change variety of chrysoberyl.
Legends claim that the discovery of alexandrite was made on the very day the future emperor of Russia became of age. Inevitably, the red and green color change stone was to be declared the official gemstone of Russian Empire.
Alexandrite is one of the rarest of all colored gemstones available today.
More specifically, it is an extremely rare color change variety of chrysoberyl (a cyclosilicate).
Despite its name, chrysoberyl, which is an aluminate of beryllium, does not actually belong to the beryl mineral group, but rather, it is classified as its own independent mineral group.
Alexandrite is the birthstone for June and is the zodiacal sign for Gemini.
Alexandrite is also used to commemorate the fifty-fifth wedding anniversary.
Alexandrite is a stone associated with discipline and self-control, which adequately explains Alexandrite's stoic personality.
The color change phenomenon seen in alexandrite is referred to as the 'alexandrite effect'. The change in color can be observed under certain lighting conditions, typically under daylight and incandescent lighting.
The Alexandrite gemstone is green when in the presence of light composed mainly of greens and blues (e.g. natural light) and red in the presence of light composed mostly of reds and yellows (e.g. incandescent light), and purple when shown under both sources of light.
Alexandrite can also display a cat's eye effect; and this rare trait can make an alexandrite stone even more valuable.