Vantaa Blue

Last modified on July 24, 2026 • 1 min read • 111 words

Swedish Blue Stone is a synthetic jewelry stone made from blast-furnace slag. They were not made on purpose, but have been cast away as a byproduct of metal ore smelting during the last centuries. While in Sweden these stones are commercially used  , nobody in Finland bothers to make a business out of them. A few hobbyist gemstone hunters - like me - have been gathering these stones over the last 50 years or so, but you can still find quite a few of these. One deposit of these blue stones is near the Pitkäkoski Rapids on the Vantaa River. I have polished a few and use them occasionally as presents.