I think I recognize those other chips as the "Pro Clay" type with "CASINO" stamped in the mold --
https://www.discountcasinogear.com/Poker-Chips-Pro-Clay-Casino-s/862.htm.
I've played with them before -- a step up from dice chips, in a good way. They are not slippery in stacks like NexGen chips are, and have nice bright colors and contrasting/different spot colors. A good starter chip. Are there any sort of hotstamps/tourney denoms on them?