Jumi

Jumi resemble humans in most respects, but they have mineral or gemstone cores embedded in their chests (and names that allude to their core's material). Their cores are intertwined with their physical and mental health: a Jumi with a damaged core may be weakened or develop a split personality, and removing a Jumi's core from their body will immediately kill them, with even the strongest surviving only briefly. Because of their cores, they do not heal the same way humans do, and human medicines are useless to ill or injured Jumi.
Jumi society includes bonded pairs of combat-ready Knights and passive Guardians, and a Clarius, the greatest of all Guardians who is responsible for healing damaged Jumi cores. Guardians generally support their Knights, either directly with magic, or through political means acting as their envoy. This pairing is not required, but is very much the societal norm.
They are a rare and dying race due to being hunted for their cores as objects of beauty, and from the belief that their cores contain special magical properties making them a historical target of mages. There is a small effort to combat the latter idea by certain mages, including referring to Jumi as "dirt" to highlight that a removed core is no different from an ordinary stone. The already weakened race was driven to near-extinction due to the depredations of a mysterious "Jewel Hunter," but a legend that any who cry for the Jumi will turn to stone does little to elicit pity
How they differer from Dragonborn:

• They look human except for the gem core, and odd color eyes
• If their chest core is removed (strength check against DC 10+Prof+Con+Wil), They start making death saving throws until either the core is returned, or they fail 3 times.