A lot has to do with the amount of moisture in the dope. Gooey tar can be dried out with a heat lamp or if stored in a cold area with low humidity. I think though that often if the dope is really dry it may be because it has had some type of powder cutting agent used. But, if it has been stored while moist it will stay moist likely, depending on humidity and if the dealer keeps the dope in their pocket and it stays warm and so on. But, gooey stuff can be frozen and dried out and made dry. Dry stuff can be warmed up and "steamed" and cut as well. In other words, a dealer can make it look the way they want to if they want to take the time. I think it all comes down to how it is stored though from farm to arm as to its dry or gooey nature. LOL, in other words you can't really gauge quality of that shit from dry or gooey texture for the most part.