Silk

Boyd’s Bible Dictionary:

(Seric stuff). Silk hardly known to ancient Hebrews. Some fine linen fabric is supposed to be meant (Prov. 31:22; Ezek. 16:10,13). Undoubtedly known in N. T. times (Rev. 18:12).

Concise Bible Dictionary:

In Ezekiel 16:10, 13 the word is meshi, and refers to some very fine substance like hair, fine silk. In Proverbs 31:22 it is shesh, which is fine linen. In Revelation 18:12 it is σηρικόν, silk.
Purple Silk