If you are going for shilajit for the first time and you would like to get all possible health benefits that it is known for then you should always be opting for pure black shilajit. You will only be able to benefit from shilajit that is in its purest form otherwise it would just be a waste of time and money for you.
Pure himalayan shilajit is usually black and has a solid appearance though it is not too hard. You can bend it with your fingers and break it into pieces that you could dissolve in water for preparation. Now shilajit may be available in different forms and different brands so picking the one that you find easy and convenient to prepare would be the way to go for you.
This is because you cannot simply buy it and then store it away without using. You will only be able to benefit from pure black shilajit if you actually use it and that too, correctly as instructed. You usually have to only use a very small quantity that you could dissolve in water and use for a while. The purest form of shilajit can last you for a very long time.
Avoid impure varieties of shilajit as you will find yourself not getting the type of benefits that you would have expected and you will also find yourself having to keep buying more of it every time which would work against your interests.