It's called the Sapphire Isle
because of the blue of its water.
Game of Thrones Season 3, Episode 4
They call it
the Sapphire Isle. Do you know why?
Game of Thrones Season 3, Episode 3
He's convinced Lord Tarth
owns all the SAPPHIRE mines in Westeros.
Game of Thrones Season 3, Episode 7
Every SAPPHIRE in Westerns
was mined on Tarth.
Game of Thrones Season 3, Episode 3
The Sapphire Isle.
Game of Thrones Season 5, Episode 4