It is western cedar, if you want, you can drive to the Eel river in CA and spend a few days looking.
I doubt this was the same wood you saw in the lobby, it was more likely Redwood root.
Redwood tends to be too large for aquarium use, but I've found a few smaller nice pieces, rarely.
I cannot collect and sell much of that, simply because it's 6 hour drive each way and much less is available and it's much harder to obtain.
If I lived near there, then perhaps.
Manzy is much more suitable to the hobby however.