Ruby or crimson amber is especially rare, being found mostly in deep mines and the oldest of bogs. Its value doesn't come so much from its rarity however as from its strange properties when burned. Producing a thick reddish smoke when burned over flame or charcoal, when any item of iron passes through it, a shower of bright red sparks appear, leaving tiny scars and scratches on the metal.

While mostly harmless in and of themselves, these sparks float for quite a distance, and pop when encountering anything solid. The spectacular ethereal beauty of these slowly twisting ember-ghosts, lighting the billowing clouds of smoke from within, has made them very popular among the most successful troupes of entertainers and in noble courts throughout the kingdoms, and ruby amber is worth more than its weight in gold.