Our world can benefit from important items that are neither supernatural nor technological. In the former case, people can attribute supernatural properties to objects that don’t necessarily have them, as is the case on Earth. Religious ones come to mind. Something associated with a prophet can be considered holy. These include the Shroud of Turin, the Holy Grail, and even John the Baptist’s head. But we also have items that were present at an important moment or which were memorably used, such as a weapon that killed a famous villain, or a possession of that villain or a hero.
Our regular items won’t have unique properties quite like those of magical or technological ones, so we don’t need much more than its description. A unique appearance makes it more identifiable in visual mediums, even if that was achieved not by design, but by usage. An example would be a sword that had no special properties but was used to kill a powerful villain and is now revered.
The origins are likely as mundane as the item itself, but needn’t be. Sometimes people like the idea that a seemingly ordinary item was special all along, but it only revealed itself to be when someone did something with it. This is mythological thinking. People may later decide that a sword which slew a victim had a property incorporated by the forging blacksmith, when he hadn’t. We can even have such characters build a reputation on this. Maybe our current hero wants a sword forged by that blacksmith, thinking it has an advantage that it doesn’t. This adds realism.
When creating a regular item, the form may matter if our characters will use it. A coveted decorative wall hanging may be anything, but if we need them to wield it as a weapon, then it needs to be a blade. If our characters won’t use it, consider making the item a less expected form, like a tea pot. If poison was in that, or it was the last one from which a ruler was served before death, this can make some think it’s special.