Phosphosiderite has lavender skin and selago hair. Her hair is unkempt, comes to a point in the back, covers her right eyes, and comes down to her knees. She has four eyes, four arms, a small nose, plump lips, and prominent fangs.
Phosphosiderite wore a sleeveless layered navy, bright violet, and light blue tunic with a rounded neckline. She also wore dark violet tights with light violet toes that had star-shaped cutouts in the knees.
She wore a sleeveless light blue tunic with a high neckline which featured a dark violet waist and bottom. She wore darker violet tights with torn star shapes in the knees, tucked into violet boots with lighter violet toes.
This is the only regeneration where she had pink eyes instead. Phosphosiderite wore a violet tunic similar to Amethyst's, with a darker violet piece underneath that had a triangular cutout to display her gemstones. She wore dark violet tights with star-shaped cutouts in the knees, tucked into short, light violet boots.
Phosphosiderite wears a white and dark violet tunic with triangular cutouts at the bottom, which creates a torn look. She wears a violet bracer with a white star and a white bracer with a violet star on her upper arms. She wears darker violet tights with lighter violet star shapes on the knees, tucked into darker violet boots with lighter violet tops.
Phosphosiderite is described as goofy and enjoys having fun, but knows when it goes too far.
Phosphosiderite used to combine Ice's stubbornness with Amethyst's recklessness into a bit well wild personality because GemCrust "[couldn't] see [Amethyst] and Ice getting too well."
However, as of changes in their relationship, she's now laid back; getting her to do much of anything would be an accomplishment unless angered or provoked. She only responds fully to really dangerous situations.
Phosphosiderite possesses standard Gem abilities, bubbling, shapeshifting, fusion, regeneration, agelessness, and superhuman strength/durability.
Amalgam Physiology: Phosphosiderite is able to summon all the weapons and control the powers of all their components and the fusions within them.
Cryokinetic Weapons: A variety of her cryokinetic skills, Phosphosiderite can summon any weapon she wants using ice; the same goes for Ice.
Spear Proficiency: Being Phosphosiderite able to summon Amethyst's whip — albeit in her own colors — and control Ice's cryokinesis, she can combine both to form a spear. This ability is not really necessary given she can already produce any weapon at will.
Pearl reacts to Phosphosiderite in a similar fashion as she does to Sugilite, though the former presents less of a threat.
There was some controversy on Phosphosiderite's summoning weapon, whether it was a spear or not.
On August 6th, 2015, GemCrust stated that it was, that it combined Amethyst's whip and Ice's cryokinesis. On May 20th, 2017, however, this was retconned to her not possessing it. Finally, on the same day as his former statement, GemCrust corrected himself, saying that, in fact, both Phosphosiderite and Ice can summon any weapon at will using cryokinetic force.
Her gemstones were changed in their current regeneration because the old ones were "very poor edits." They lost the blue hue the old ones had.
Phosphosiderite is Ice's favorite fusion to form; the only one that could run against her would be Shattuckite, the fusion of her and Jasper. Though the former is a little more fun to be.