Why is it sometimes, when you ask your chief to point out rare collectibles there is nothing to see??? Can they hide behind trees, tomb stones, huts etc or am I just going blind lol

Yes they can; in that case, all you'll see are sparkles. Also remember, that the chief doesn't actually point at anything - he just makes a rare collectible appear. It can be anywhere that collectibles appear. For instance, he'll never point at a turtle shell, because his animation doesn't make him point that direction, even vaguely.

If you make the chief give a lecture straight after pointing out a rare collectible, all the peeps rush to listen to the lecture and it's much easier to find the collectible - this is especially useful if your village has lots of peeps!

Twice recently I've set my chief to point out a rare collectible, only for it to start raining as he's started his little dance before pointing it out.

That has meant I got no collectible at all. Only mushrooms appear during and for a little while after the rain. And, of course, I had to wait another 24 hours ...

Ho do you ask the chief to point out a rare collectible. I am missing 2 corrals, 3 shells, 1 feather and 1 piece from the slab. I have level 2 of everything and level 3 of alchemy. ALso I am from the nature faction. Man this game is so addictive. If someone can help me understand how the chief points to a rare collectible or makes it appear.

If you click on the question mark (?) next to Leadership Technology, there's an explanation of the chief's special abilities and how to use them.

Duh!...Thanks LadyCFII. so that means I still have 100,000 tech points to collect. Thanks again.

It seems to happen rather often, so I have been wondering about that as well. Since I have always looked very closely I don't think it is just too well hidden to find the pointed out collectible.
I came up with this idea: the chief randomly points out a rare collectible and often enough You end up with one You have already found before. But tablet pieces never show up twice - they are unique. So maybe, if the chief still "chooses" a rare tablet piece to show up from an unseen list that has already been obtained before, You are simply unlucky and nothing will show up that time. I think that would explain why it keeps happening that You loose a chance to get a rare item.
But maybe I am all wrong and it is some mystical magical/natural reason behind this and You would only know, if the Chief's robe would fit You.

That may be an explanation!

... it could be fun