Just assumptions:

I wouldn't be surprised if "Demicrystals" come from desynthesizing high level gear.

A lot of new items require grand company seals.

We have a lot of new items. Half will probably come from Lore tomestones and half from gathering. Just a list I've made so far. But I wouldn't be surprised if the Hemicyon hide comes from new Diadem.

Tungstite
Titanium Carbide
Luminium Ore
Scintillant Nugget
Hemicyon hide
Teak Log
Star cotton boll
Invisible ink
Goblinol
Zeolite Ore

Just judging by the names, I'm guessing the tomestone items will be
Scintillant Nugget
Hemicyon Hide
Titanium Carbide
Invisible Ink
Goblinol

Gatherable items will be
Teak log
Luminium Ore
Star Cotton boll
Zeolite Ore
Tungstite

Now I wonder where we will be able to get them?

Saurian leather had been selling for like 100 gil on my server so I was just throwing it all away!! I should have been saving it!

But I wonder if people somehow knew Gold Ingots would make a comeback? I think the prices on my server jumped from like 500 gil each to 8,000 gil each, if I recall correctly...
I also saw some people making a lot of platinum ingots just yesterday.