Flaming Sword Rock Carving (Antiquities?)

They're not going to share any expertise or spend time & effort on an item they can't/won't sell, so first they decide if an item makes the cut. If they had thought this has great age on it You might have got a bit more out of them.

If you, like me, you imagine big name auction houses having a horde of experts who closely examine all items accepted for consignment. In truth, they mostly accept the consignor's representation of a thing, delving into it themselves only occasionally, such as when they suspect it is a previously unknown da Vinci.

They didn't think yours was like this:

https://www.liveauctioneers.com/news/top-news/norwegian-archaeologists-find-worlds-oldest-runestone/