@LeoFox: thank you; I thought that I may have recalled that from here somewhere, among other places... Searching for 'minerality in wine' brings up an awful lot, most of which I will ignore.
@Baisao: I think that that is yet another area where there may be disagreement. I wouldn't want to pretend to be particularly experienced with wine (or tea), but 'flintiness' in wine is something which I think is rather different to 'minerality', and it seems that these authors miss that, at least to my quick read. I think that flint is a distraction.
Flint does seem to be associated with a 'reductive' approach to winemaking, especially for certain white Burgundies (some winemakers have made it rather famous, and they aim intentionally for that style, even though it leads to thoroughly unhelpful reviews, to the effect of: 'Nice wine. Hard to tell. Could be great. Lots of reduction. Pretty muted. Try it again in 2030. 88-93+ points.').
Minerals seem to me to be something else in wine; something fresh and vibrant but difficult, beyond mere acidity, and which cuts through or assists with fruitiness, and gives it some backbone or substance. I would guess that it could have something to do with tannins (even for white wines), and a combination of many other things that I don't know about. I'm not good at describing flavours and aromas, so I won't try any further. I'm sure others will do a much better job.
I guess that it's an overall feeling or sensation, for which people try to ascribe a word, even though that word, taken alone (and without context, especially without trying the wine in question at the same time) is mostly meaningless.
I could describe a wine or a whisky, or a tea, as being 'chalky', but no-one would think there's any chalk in there. Minerality just seems to be another one of those imperfect descriptions.
As for tea, minerality tends to suggest to me a combination of roast, tannin (or equivalent), pleasant austerity, and a feeling that it is more than the sum of its flavours. Calling it a 'flavour' seems wrong. And I think that it can't only be the roast, because I've had lighter styles that have had that quality.
But it's not something that I aim for. It's just a part of the tea, sometimes.
I'm tempted to say that 'a sense of place' is a better use of language than 'minerality', but it's probably much worse.
Andrew