(Em português)
I prefer to keep my teas and spices in glass jars, because this material does not absorb odours nor flavours, meaning it can be reused without interfering in the food I store - besides, whenever I judge it necessary, I can sterilise the jars and lids (only the metal ones).
Unlike plastic, glass won't allow for aroma and flavour characteristics of the food to be lost, for glass stops aromatic substances from evaporating. I think it is very functional, since the jar's contents are always on display, plus I find it pretty.
Furthermore, it is a sustainable storage solution, because most of the time I put to use packages that would otherwise be discarded (honey, jam, dulce de leche, juice, etc); even if I bought a set of identical containers, it is a material that lasts long.