Israeli researchers working in the Timna Valley near Eilat have found three textile scraps colored with the biblically described “argaman” royal purple dye. They have been dated to circa 1,000 BCE – the era of King David. They were found in the area known as “King Solomon’s Mines”.

https://www.timesofisrael.com/ancient-cloths-with-royal-purple-dye-found-in-israel-dated-to-king-davids-time/