We do know from Bianca and some of Cole's comments that lyrium on surface is alive, (she's made no distinction between lyrium on the surface and the mined one), angry (according to Cole) and the one on the surface keeps humming, singing and infecting, even if it does so at slower or less aggressive rate (unless it's cultivated from people, or so it seems).
It's possible that the purity of lyrium near the Titan makes it impossible for truly pure lyrium to be infected... but I'd say that while the lyrium reaching the surface may be less pure or potent, it's definitely still alive.
And then there's ancient thaig itself, in which we also see pure veins of Red Lyrium...
When I say "mined Lyrium" I mean Lyrium that isn't circulating within a Titan, that includes lyrium found on the surface as well as underground. I know it's "alive". That definition however can be interpreted in many ways. I compare it to DNA and the fact that it has an imprint of the Titans left within it, a memory of what was. It's why the song can still be heard. Valta talks about remembering things long forgotten when she connects with the Titans. However, Dagna also experiences things while working with a lyrium rune, almost like memories from the Titan it came from.
as for the Red lyrium found in the Primeval Thaig:
What I think happened with red lyrium that's more likely is that once the Dwarves branched off from their brethren, chaos ensued. Think of it, their whole outlook on life would have changed. They would probably relish their freedom yet feel like something was missing, an emptiness where once there was a song, warmth and reassurance. Without the Titan symbiosis, I think Dwarves found different ways to cope, some better than others.
I believe that the profane for example are a product of this hardship
We who are forgotten, remember (forgotten by the Dwarves who stayed with the Titans)
We clawed at rock until our fingers bled, (they either wanted to rejoin their brethren, begging them to let them return to the stone or they wandered the deep roads and found themselves literally trapped or imprisoned)
What Valta described comes to mind "fell into a warm light's embrace", as if returning to the Stone.
We cried out for justice, but were unheard. (neither the Titans nor their brethren could hear them)
Our children wept in hunger, (literal)
And so we feasted upon the gods. (they feasted upon Titan's blood, without being part of them, which, I'm guessing, is blasphemy. It's also noted that they still rememeber the Titans, so this is very old indeed)
Here we wait, in aeons of silence. (silence, because they can't hear the song)
We few, we profane (based on their actions, they consider themselves profane, literally split from the "gods" "teachings" (in this case the hive mind or the empathic symbiosis they had with the Titans).
I think something similar happened with the Primeval Thaig. I believe that some Dwarves who separated from the Titans couldn't cope with the silence (the lack of Titan symbiosis). This drove them to look for an alternative. I believe Dumat called out and they heard. I think they willingly corrupted the lyrium and were in turn corrupted in order to hear the calling, something to fill the silence. Their connection to lyrium might have still been strong, stronger than it is with modern day Dwarves at the very least. This is probably how red lyrium came to be. The Thaig might have been shaped with magic before it was corrupted also, keep that in mind. I don't have any details, but it seems like the most logical explanation in my mind.
Whatever the form of lyrium, 'pure' or 'mined', it doesn't seem to be affected or infected by darkspawn, but by some kind of special process - otherwise we'd see Red Lyrium long before Hawke and Varric discover it in ancient thaig.
In fact, it seems that the only way to 'infect' the lyrium - in surface or not - is through processes Corypheus has discovered, one of which involves using living bodies as apparent 'hosts' for growing Red Lyrium.
Not necessarily,
"But following the opening of the Breach, it began appearing throughout the surface of all of Southern Thedas in crystalline nodes. These crystals grow almost anywhere, though the composition of the earth can affect their growth"
The breach seems to have affected the red lyrium as if pulling it to the surface, a if the fade itself was calling out to it. Also Red lyrium has the effect of thinning the veil. If the red lyrium was only found in the deep roads and was sealed away or secluded, that could easily explain the lack of its appearance until the breach opened. The fact that Corypheus later found out it was actually infected by the blight and decided to cultivate and experiment with it also would have driven its spread through Thedas and it's growth.
In Redcliffe we see Fiona being infected, and alongside her, the companions we took, which I highly doubt have joined Corypheus, even after Inquisition fell. We also know that people have been disappearing, and we actually discover that the reason for their disappearing was to speed the grow of lyrium in many red lyrium mines - and especially in Emprise du Lion. In fact, we do know both from Emprise and quests in Emerald Graves that Corypheus and his lackeys have been amassing as many people as they could to keep cultivating Red Lyrium. So no, this wasn't just a matter of "recycling soldiers".
Why are you talking about our companions? I never talked about them joining Corypheus, I was stating that the soldiers under Corypheus' orders mined red lyrium from failed experiments and soldiers that were in later stages of infection that couldn't fight for him etc. I was giving examples as to the fact that Red Lyrium doesn't *compel* you to mine it. Fiona was infected and she is the one that explains what they do with people that are in the advanced stages of red lyrium infection, like she was. Being immobile with immense growth, her body is ripe for the "picking" (pun intended). As I stated above, those disappearances were for many reasons namely experimentation and propagation. I wasn't just saying that it was just a matter of "recycling soldiers", that's just a smart way of using the soldiers that can't fight anymore. Corypheus used the nature of red lyrium to his advantage, using people to create red lyrium at a faster rate, in order to fuel his powers and his army ergo "recycling" for renewable energy.
How would that be disappointing? At this point we don't really know what Titans and their role is - it's however possible that they're part of greater whole and dwarves might have specific role, just like elves and humans or other races/Titans do in 'ecosystem' created between them. This might actually even explain Abelas or Solas repeating incessantly that elves are now not what "they were meant to be", as if they've had a specific role to play.
Also - why would dragons 'ruling the skies in a time before Veil' would mean that they didn't originate from Titans? When we know that "the blood of the dragons is the blood of this world"? What if Titans themselves are in fact draconic beings - or 'first children', with dragons actually being second and all other races beings somewhere next in line? We also have no idea whether only underground Titans or Titan-like entities exist, either within Thedas or the Fade/Void itself.
It would be disappointing to *me* because they just introduced a very interesting piece of lore that make the Dwarves unique and that explains a lot of things that have slowly been built up and hinted at. Having everyone originate from the same source would in my opinion, disregard this revelation and lessen it.
I believe what Abelas or Solas meant when they said elves are now not what "they were meant to be", is pertaining to the fall of the Elvhen people. Given they both look down on the Dalish, calling them foolish and children, it wouldn't really seem like a stretch.
I also believe Titans ruled the earth as Dragons ruled the skies. I also believe Elves are synonymous with Dragons the way Dwarves are with Titans.
Lastly Ancient Elvhen people would seem to have been hunting the Titans and Dwarves.
"In this place we prepare to hunt the pillars of the earth. Their workers scurry, witless, soulless. This death will be a mercy. We will make the earth blossom with their passing."
With their knowledge in mind, why would they do this if they had some connection to the Titans.
Titans are the stone, they are part of the earth. i doubt they reside in The Fade given their nature.
The reason we can find lyrium in The Fade however?
"Why are the laws of the Maker bent but not fully broken? Why does a book not turn into a dragon, or a statue explode into countless shards of energy? The answer, I believe, lies in the fact that the items we see in the Fade were most often made by the hands of men".
More than that though. If we are to assume Titans were the antithesis to The Fade or rather that Titan "magic" is a different aspect of the same coin like yin and yang or nagative and positive charges, than we can assume that they can influence each other to strike a natural balance. I believe Lyrium found in the fade is the product of a time before the veil. I also think it might keep the "laws" of the maker from being completely broken as referenced in that part of the codex.
Anyways this last part is what I believe, part of my theories, because I think it makes sense. I'm not suggesting its how things are, simply the way I think things are.