Ocean tiles during mining counts as ore

[Fostik]

Probably not all the tiles, but replaced with ocean border.

There is a gif that shows ocean border tile, and also shows that there is no any other ore tiles around. When I'm digging a tile it still shows me "Something glimmers in the vein." from miner's credo.
https://i.imgur.com/n73Em6R.mp4

Not a big deal, but it was quite confusing.