According to the developers on-stage, they were designed to feel like the " ultimate prize ": according to the team, they look and feel like real gold
Source: Wizards of the Coast Main Genre Fantasy Release Date August 5, 1993 Created by Richard Garfield Character(s) Jace Beleren, Chandra Nalaar, Liliana Vess, Garruk Wildspeaker, Nissa Revane, Ajani Goldmane, Nicol Bolas, Teferi, Gideon Jura, Sorin Markov, Ral Zarek Video Game(s) Magic: The Gathering, Magic the Gathering Commander, Magic: The Gathering - Battlegrounds, Magic the Gathering: Duels of the Planeswalkers 2012, Magic: The Gathering - Duels of the Planeswalkers, Magic: The Gathering Duels of the Planeswalkers 2012, Magic: The Gathering Duels of the Planeswalkers 2013, Magic: The Gathering Duels of the Planeswalkers 2014, Magic: The Gathering Arena
For example, Amber is meant to be a support Ink type, whereas Amethyst is meant to be more fragile ability users
5 Cogsworth Illuminary Watchman Versatile and fits well into Amethyst nicely