NBT data of block in inventry not being transferred when placed

I have been manually adding nbt data with commands and verifying it with this procedure: 

public class SpecialInformationProcedure {
    public static String execute(ItemStack itemstack) {
        return itemstack.getOrCreateTag().getDouble("luck") + ".";
    }
}

I apologize for not knowing how to upload images, this code block is the best I can do