Bring Back Transparent Materials

[Alam_K]

i can understand the need for pearls in the new DLC buildings, but it shouldnt be to the detriment on obviously transparent buildings to also take pearls as alternative when pearls are clearly not transparent. i suggest that the transparent category keep its place and materials, but also add a new glassy category that includes all transparent materials and also pearl. also, as an addition, i think marble blocks would be very nice if built using pearls, so i would also suggest adding pearl into precious rock category