It can be turned into a scepter that Stella usually uses to help cast spells, or teleport herself and other people to a certain place. According to Stella, the ring is made of 6.1 pure magic.
It is cyan blue. When it is in its ring form, it is a ring with a sun-shaped circle. Same goes with the scepter form, except it is now much bigger and instead of the ring there is long staff with the sun-shaped circle being on its top.
The base is cyan blue. It has six orange jewel spheres on top - one in a middle and other five around it forming a pentagon. While transformed in a scepter it has a cyan blue sphere on top of it, but instead of the big wheel alike ring around it, it has six orange jewel spheres, once again - one in a middle and five around it forming the pentagon. On outside there's also five small spheres attached to the bigger ones.
Chimera's scepter is different. It is a purplish, darker version of Stella's Scepter that's shaped like a diamond with a purple jewel.
It is a part of the lineal right of the Princess of the Sun and Moon of Solaria and has been in the royal bloodline of Solaria since forever. It was forged so long ago that no one remembers when. It was carved out of a stone, immersed in the Spring of Light which still flows in the universe. The ring was also considered as one of the most precious gifts offered by the Dragon Flame.
Stella was seen using the ring as its scepter form many times. Knut attempted to steal it from her two times during her time being at Earth, but Bloom interfered both times and the Specialists arrival at second time drove Knut away. The Trix still wanted the Solaria ring, attempting to steal it in the dance of Alfea and Red Fountain, but the Winx realized their plan and switched the eggs that were supposed to contain the ring.
The Trix finally got the ring after tricking Stella into an abandoned house, but since she did not have the ring in her possession at the time, they used Stella as a hostage against the Winx and Bloom eventually gave the ring to them. However after trying to see if it contained the power of the Dragon Fire, Icy came to the conclusion that they were mistaken.
Researching about the ring, Bloom finds a magical items' book little explanation about it leaving them with no clue as to why the Trix wanted the ring. The Winx came later to Cloud Tower to get the ring back, which resulted in their detention and having to clean up the entire school.
Mostly used on the firsts episodes to illuminate dark places, defeat two monsters, help plants to grown as well as to teleport them two times.
In "Magic Bonding", it is explained to Sky that Stella must know the location they wish to be teleported very well, otherwise they might end up anywhere.
Stella used the Ring of Solaria in the eighth episode of Season 3. She used it to defend her father, Radius. Stella sacrifices her life for him and earns her Enchantix. Stella doesn't use her ring as a weapon much anymore after receiving her Enchantix, but she still did use it to teleport the team to places like Andros and Linphea. It is unknown where she keeps her ring during present time, but it is possible it is kept at Solaria or in her jewelry box.