So far, the PCs know almost nothing about what items the dwarves of the Coldstone clan have available, or what it will take to buy it. But they do know of one rune made by their smiths:

Lesser Weapon Rune: Ember
Requires Attunement
Deals +2 damage as fire damage to each successful weapon attack.
Activate as a Bonus Action after hitting to deal 1d4 additional fire damage.
Activate as an Action to make the weapon glow to 10’ good illumination, and another 10’ shadowy for 1 minute
Activate as a Reaction to block a weapon attack, reducing damage taken from that attack by 10, and shattering the runed weapon.