Yes, a spice jar is probably the best. Something air-tight and glass is preferable

If you leave your weed in a plastic baggie for too long many of the trichomes and small crystals stick to the bag. Also, after a while, it can start to taste "plastic-y" when you smoke it.

Bagging anything is bad in the long run. They are not airtight, they have tiny little holes in them for air to get into.