here's my speculation (wishful thinking really:P)
they're an organic sentient species, but with a outer crystal shell or skin making them golem-like (not actually golems)
for their religion they have a giant crystal core at the center of their city, worshiping it.
this crystal could be a simbiot to these creatures, so all their culture (looks,architecture, commerce, etc) would be related to this crystal.
and their society would be restricted to their environment due to their symbiotic nature with the core crystal.
i can imagine their city being similar to orzammar but with a crystal theme instead of just rock.
and as a community, i think they would be similar to the city elves and dwarves, tough and rough but very close like a family.
It would also be very insular and quite possibly very hidden. If proximity to the crystal is necessary, then they would not wander far from the "hearth stone". It would quite literally be the center of their universe. I can imagine isolated communities, perhaps interlinked by roads that had crystaline veins. This would allow them to stay connected and possibly communicate with other "tribes"
about their look, more or less like this but with some organic tissue still showing