clear quartz and rose quartz are two wonderful gemstones to have if you are having a difficult time/grief. They are both known to calm you. howlite is another gemstone that is used for calming. And, then also the beautiful Lapis lazuli stone! it is very calming and soothes nerves and also helps to keep the body and spirit well balanced. This stone is also recommended for those experiencing depression, so it should be good with grief, as well, I would think.
As for herbs, I like to drink chamomile tea. it really relaxes me and is also fantastic as a sleep aide. Another herb would be the lemon balm or perhaps lemon verbena, which are both known for its calming and soothing abilities. then, there is also peppermint, which is widely available, but personally, I don't care for that.