Whoever originally added it added it as a slate mine, which has been corrected, but uncaptioned photos take the original refkey value of the mine which includes the mineral type.
The main culprit here is me - I've not captioned my photos. Will do ASAP.
Longer term this is an area I need to fix, changes to mines need to cascade down through albums and photos.
Don't worry though, it's not an indicator of a bug or issue, just something I didn't anticipate when I originally wrote the site.
my orders are to sit here and watch the world go by