Each ring on a Lienid's fingers represents a family member. Saf has fewer than he would like.
Bren's ring is gold with a single, tiny piece of kunzite. It was the first ring he bought when he returned to Monsea, looking for the sister he knew existed but didn't even know yet (though not his first ring; he has others for the sailors and Lienid people who brought him up on the sea). Now that he does, he knows that kunzite is a terrible idea for his sister, strong-willed and sharp and disinclined to pink. But he had chosen it, so it stays.
He chose the rings for his parents with her help. They had been instrumental to the resistance; it was part of why he was sent away. Through Bren, he also knows they were warm and missed him daily. His father told bad jokes. His mother liked to grow primroses, small bushes up against the wall of their house, before it was burnt. Before the first one was burnt. He wears a thick, plain band for his father. His mother's ring is engraved with primroses, tiny and precise.
Tilda and Teddy were easy to add. Tilda was already part of Bren's life when he came back to it, and befriending her brother didn't take any special effort. He was glad of Tilda to keep Bren happy, and gladder of Teddy for himself. Tilda is charoite, a row three of small purple-grey stones across the top. He thinks they set off Bren's ring nicely. Teddy's ring is engraved to look like the edges of many pages of paper, where all the words in the world could be contained.
When he leaves the city with the party heading far east to the Dells, he makes sure to stop and choose one more. He finds a delicate band worked into swirls that remind him of the slow eddies of the river, set with alternating stones of yellow sapphire and the smoky quartz he knows was her mother's choice for her. It does match her eyes well. The Lady Queen must have her place, after all, upon his empty finger.