Ruby has light red skin, dark maroon hair, and is slightly taller than Steven. She wears a maroon and red-violet tank top, a red-violet headband around thick, outgrown hair cropped at the neck, mid-thigh length burgundy shorts, and pointed red-violet boots.
Ruby's appearance during the start of the show and prior to it is unknown as Garnet did not unfuse.
|Ruby wears a crimson bandana around her head, just above her eyes. She also wears a crimson sleeve-less tank top with burgundy shorts. She also wears crimson ankle boots.||
"San Deigo Comic Con"
She takes on Garnet's strength and courage, contrasting Sapphire, who embodies Garnet's cool nature and kindness. She seems to put the well-being of Sapphire over all else, as she immediately made sure Sapphire was safe and responded "Who cares?!" when Sapphire asked her if she herself was okay. She also seems to not be very conversant, a trait which she carries onto Garnet, as Ruby mumbles and speaks somewhat awkwardly.
Unlike Garnet, Ruby doesn't possess future vision. Joe Johnston confirmed that when she complained about not being able to "see" (use future vision), it was because she was so used to having that second sight while being fused with Sapphire.
Ruby, like all Gems, has some degree of super strength, as she was able to shake her cell by slamming her fist against the wall, causing Steven to lose his footing. It is also shown when she was able to lift Sapphire off her feet with little to no effort.
She and Sapphire have a romantic relationship, shown when she immediately panics when realizing that the two have been separated and becomes reckless trying to find her, running around without checking if Peridot and Jasper are around and loudly shouting for Sapphire whenever she stops singing. When she finds Sapphire, the two embrace and Sapphire kisses away Ruby's tears, showing their romantic relationship. Ruby cares strongly for Sapphire's well-being as she expressed deep concern for possible injury. Garnet's dialogue in "Love Letters" implies that Ruby and Sapphire's relationship developed gradually over a period of time.
At first Ruby seemed cold and distant towards Steven due to wanting to find Sapphire as quickly as possible. Despite this, Ruby cares deeply for Steven evident by trying to tell him not to put his hand through the force field for his own safety. Also Garnet says that both her and Sapphire had already loved Steven when he asked if he made a good first impression. She was also upset by the fact that their plan of revealing themselves in Steven's birthday had failed, apparent when she said to Steven,"Oh great! This is just perfect! and "Don't look at me."
Pearl and Amethyst have been aware of Garnet's true identities for several millennia. Their perception of the two while separated remains unknown, but given their good relationship with Garnet it can be assumed it is a positive one.
Upon encountering The Cluster, Ruby and Sapphire were both disturbed to the point of almost defusing. While Ruby reacted with the most verbal anger and outrage at what Homeworld had done to their fallen friends, it was Garnet's right eye that represents Ruby that started crying indicating that she was deeply saddened as well.From their own comments, as well as that of Garnet herself, it can be assumed that they knew the individual members of The Cluster.
- Ruby's gemstone can only be seen twice in "Jail Break."
- Garnet and the other Crystal Gems had planned to wait for Steven's birthday to introduce Ruby and Sapphire to him.
- It is unknown whether they will still do this.
- Although she was not formally introduced until "Jail Break," her silhouette, along with Sapphire's, can be seen when Alexandrite unfuses in "Fusion Cuisine." To the left of "Garnet" is seen as Ruby, and to the right of "Garnet" is seen as Sapphire.
- Ruby and Sapphire are lovers, as shown by Ruby's desperate desire to find Sapphire, and the kiss that is part of their fusion dance. It also explains why they chose to stay as their fusion, Garnet. 
- When asked if Ruby was blind from when she says "I can't see", Joe Johnston merely stated that she was "used to being fused with Sapphire, and so, used to having two types of vision." 
- Ruby is the birthstone of the creator of Steven Universe, Rebecca Sugar.
- Ruby and Sapphire both lack stars on their outfit.
- It was revealed in "Love Letters" that her and Sapphire's relationship was a gradual building up over-time.
- It's possible that Ruby and Sapphire both have rooms in the Crystal Temple, due to the fact that they both have their corresponding gemstones on the door.
- Ruby's gemstone location is not symmetrical, along with Sapphire's.
- When fused as Garnet, however, their combined gemstones become symmetrical.
- Ruby is the second shortest Gem, the shortest being Steven.
- However, she is the shortest pure Gem, given that Steven is half-human.
- She and Sapphire talk to each other individually through Garnet in "Keeping it Together".
- Ruby and Sapphire are both named after varieties of corundum (crystalline aluminum oxide, chemical formula Al2O3).
- In the extended theme song, Ruby is shown to be cracking or holding her knuckles, a sign of toughness, anger or that she's ready to fight, while Sapphire is gracefully holding her hands together, interlocking her fingers, this shows that she is calm, graceful and passionate.
- Ruby is a gemstone of emotion, associated with passion, strength and anger. This shows in Ruby's emotional temperaments and overall emotional/angry attitude, as well as her strength when she shakes her cell and lifts Sapphire.
- Ruby is the birthstone for those born in July, and is also the zodiacal stone for Cancers.
- Ruby is a variety of corundum that gets its red color from chromium.
- The vivid red color of ruby also means that it is associated with desire, and it is thought by some to be a stone of love with an aphrodisiac effect.
- Ruby is considered as one of the four precious gemstones, together with sapphire, emerald, and diamond.
- Ruby's chemical formula is Al2O3::Cr+3, where chromium, as an impurity, make rubies take an intense red coloration.
|Ruby's gemstone is located on the palm of her left hand, and has a square facet. As seen in The Return and the flashback in Jailbreak, it has a light blue ring around the edge (normally hidden inside her hand), and is flatter on the back.|
|Ruby's gemstone as it appears on Garnet.|
|Ruby's gemstone as it appears on Sugilite.|
|Ruby's gemstone as it appears on Alexandrite.|
|Ruby's gemstone as it appears on Sardonyx.|