Sixty-four Pixel Colonists

Mold could be part mineral, yes which would explain it's hardness but that wouldn't explain it's sudden growth.
Also as of the color, there are red vegetal pigments.

When we have a lab we can anayse it in more details. In fact if it can grow, is hard and has no adverse effect on human biology.. it could make an interesting building material on top of plasticarbon.

Problem is, right now building a lab is like the radar, even if we had the resource to build it, we'd lack the power to run it. e can still get someone on designing the plans for it, tho.

As for the obelisk of plasticarbon... I'm compelled to say to keep it for now. I'm not sure if the blueprints on itself will be indicative of what's it's supposed to be. But the structure is unfinished, unsettles the colonists, and has no apparent benefit or effect, and therefore, it would probably be best to scrap it. I fear that it may be of malicious nature.

(Couldn't it just be Shiva flagpole in truth. ?

As he mentioned he built it without authorisation ( he took the plastocarbon from the tank as caught by camera and programed the construction drone) and used topological repport to make sure it would use as little plasticarbon as it can which explain the strange architecture.

But of course only Shiva and Tom know that and because they are both idiots bad comunicants, our other colonist at home are panicking over nothing. If that's the case that is.

If it genuinely alien, I'd rather keep it for futher study. I mean i's a first contact artifact, it's value is just.. incredible.)