Onyx is a black mineral often used for decoration in the known world.
Altars in septs can be inlaid with onyx, mother-of-pearl, and lapis lazuli. Within the Great Sept of Baelor, a chamber has carvings of the Seven with eyes of onyx, jade, malachite, and yellow moonstone.
The helm of Ser Lucas Inchfield was decorated with an onyx spider to represent House Webber. While disguised as Egg, Prince Aegon Targarye kept hidden a gold and onyx signet depicting the arms of his father, Prince Maekar Targaryen.
A Clash of Kings
The Tourmaline Brotherhood gives Daenerys Targaryen a dragon crown with three heads carved from ivory, jade, and onyx. Xaro Xhoan Daxos gives her a thousand miniature knights carved of amber, amethyst, beryl, jade, onyx, opal, and tourmaline, with armor of silver and gold.
A Storm of Swords
The seven-sided golden chalice given by Lord Mace Tyrell to King Joffrey I Baratheon has an onyx stag to represent House Baratheon. During his wedding feast, Joffrey wears a doublet with onyx studs.
A Dance with Dragons
- A Clash of Kings, Chapter 18, Sansa II.
- A Feast for Crows, Chapter 43, Cersei X.
- A Clash of Kings, Chapter 40, Daenerys III.
- A Dance with Dragons, Chapter 63, Victarion I.
- A Feast for Crows, Chapter 40, Princess In The Tower.
- A Dance with Dragons, Chapter 1, Tyrion I.
- A Dance with Dragons, Chapter 48, Jaime I.
- A Game of Thrones, Chapter 3, Daenerys I.
- A Game of Thrones, Chapter 19, Jon III.
- A Feast for Crows, Prologue.
- The World of Ice & Fire, The Bones and Beyond: Yi Ti.
- The Sworn Sword.
- A Feast for Crows, Chapter 12, Cersei III.
- A Storm of Swords, Chapter 59, Sansa IV.
- A Storm of Swords, Chapter 60, Tyrion VIII.
- A Dance with Dragons, Chapter 38, The Watcher.