Some spices are heated to kill off any possible insects. A few years ago, Szchuan peppercorns were infested with some kind of bug, so the US banned all imports of these until steps could be taken to prevent the bugs. Pimento is a term used for a specific type of sweet red pepper. I grow these instead of most bell types as they are thicker meat, and ripen sooner. I roast them to remove the skins and can them. The allspice might be a 'fruit', and is grown mostly in Honduras. It may not thrive in Z7. Usually its better to buy whole spices and grind as needed. My little coffee grinder (blender type) has seen more spices ground in it than coffee!

If you want to know if the type of allspice you have is viable, crush it so the hull just breaks. I have never seen on that was not hollow.

Allspice berries are harvested before they are fully ripe. Inside the berry case, when dried, any seeds should rattle, but of course there won't be seeds if they haven't developed yet! That means that what you buy at the supermarket are unlikely to be viable.

As Ksrogers said, allspice is frequently infested with bugs, so they have to be chemically treated. The problem has become so serious, that Australia has banned ALL herbs and spices from the Americas from coming into the country - in case they contain the allspice/pimento bugs. Chemically-treated berries are also unlikely to be viable, so you're between a rock and a hard place, aren't you?