Tile Improvement doesn't provide the resourse

[DieMedium]

Hey guys,
I'm kinda new to the mod, so I've got a question.
I've encountered a problem when I have already improved a tile (with Stone resourse) but Stone doesn't show up in the city menu and the buildings that require access to Stone are unavailable.
First I built Stone Tools Workshop (which was said to provide Stone) on the tile but nothing seemed to change, so as soon as I researched Mining tech I replaced STW with Early Quarry (which was also said to provide Stone). To no avail.
Attached you may see the screenshot of the tile hoverover.

Thank you for your help!

 

[Fermongu]

Is the resource fully conected to your city by trails?

 

[Thunderbrd]

That's what struck me looking at that picture... you need to build routes from the city to the resource plot to get the resource as well.

 

[DieMedium]

wow, thanks.
haven't played civ4 for several years and it turns our I've forgotten basic mechanics

 

[Raven Destroyer]

happens to the best of us at times