Natural? In the sense in which I presume you mean the term, No.

Here is a clarification of the category that will hopefully make things nicely more muddled. :-)
The words on the card refer to something that can be reasonably interpreted relatively narrowly, or a bit more broadly. In both cases we are talking about something primarily mineral, and I can do no more than make educated guesses about the vegetable component. Under the narrow definition, my guess is that the vegetable component is present, but small. Under the broader definition, the vegetable component is surely more prominent, but the mineral component still clearly dominates.

(To be honest, you will probably make more progress if you ignore the vegetable component.)

Bog standard food for steam locos.