Nickel sulfide is a moderately water soluble nickel source. It may be the only nickel on your hands or a silver bullet in a sulfate rich environment. In the right hands it is the en vogue for a good reason. Besides, it has the right formula. The good news is that it is readily available in most volumes. So why not make the most of it?
There is a small aforementioned that is a bit more shady. If the answer is yes, then you are not the first person in your circle. This may well be the case because nickel has a curious chemistry that is a veritable gold mine for scientists and hobbyists. Aside from its many sulfate compounds, it is also an excellent source of borates, nitrates and phosphates. And since nickel is a member of the octahedron, it is not prone to corrosion. Thus, its oxidation state is largely stable, which makes it a very desirable commodity in the metallurgical industry. However, nickel sulfide is not for the faint of heart. One of the few downsides is that it is rather expensive to extract from its source materials. To mitigate this, it is often distilled from molten sulfate solutions. Thankfully, there are several companies that offer this service. Besides, they are in the business of extracting the coveted metal from its ore.