The first written account of agate was by Greek philosopher and naturalist Theophrastus (ca. 315 BCE) who mentioned in his book De Lapidibus (On Stones) that agate was named after the Achates River in Greece where it was found. The earliest known carved agates come from Mesopotamia. Carved animals that date back to between 2000 BCE to 1001 BCE have been found. The Mycenaean used agate for seals, cylinders, and jewelry. The Pylos Combat Agate was found in a Bronze Age grave that dates to 1450 BCE near the Palace of Nestor in Pylos, Greece. The Greeks and Romans used agate for signet rings and tableware. Agate was used frequently throughout the Middle Ages for decorative objects and the cutting industry in Idar and Oberstein, Germany was developed to take advantage of the quartz resources in the surrounding area. Agate continues to be popular today and is a favorite stone for modern day lapidaries.

Source: https://www.gemstones.com/gemopedia/agate#History