The Scaled Umbrella is a Fourth Grade Artifact that was discarded and later picked up by Riko.
It is a processed Artifact created from Charcoal Sand, a Third Grade Artifact, by being compressed into bars to form an umbrella. However poor craftsmanship resulted in an overall degradation of the grade. Nevertheless, the light weight and strength of Charcoal Sand hasn't been lost, meaning Riko can use the Scale Umbrella as a shield.
Riko brings it with her on her journey, but it is destroyed in the 4th layer when Reg uses it in the fight against the Orb Piercer, whose needles pierce it easily.