Its success has been led by managing director Chris Hansen.
Hansen was appointed as MD and CEO of what was then known as Barra Resources in May 2021.
The New Zealand-born geologist was looking for new opportunities early last year after returning to Perth from a five-year stint with private equity firm Appian Capital in London.
"I reviewed a whole host of different opportunities, most of which were valued at multiples of Greenstone Resources, or Barra Resources, as the company was called at the time," Hansen told MNN.
"On some advice, I took a closer look at Barra and leveraging my due diligence skill set, very much formed a differential view on the assets Barra had at the time, and I think they were assets that the market had largely ignored for the last 10 years."
Those assets include the high-grade Burbanks gold project, outside Coolgardie, and the Mt Thirsty cobalt-nickel joint venture with Conico, near Norseman.
Barra had suffered from a lack of cash, direction and leadership.
So much so that when it was announced that Hansen was joining the company he got multiple texts and emails questioning his decision.
"I sort of explained to them that having reviewed well over 500 different mineral and mining projects over the past eight or nine years, you start to get a sense of what works and what doesn't work," he said.
"And I think in the case of the Barra assets, or Greenstone as we are now, being Burbanks, Phillips Find and Mt Thirsty, they're what I thought were fundamentally great assets, but, in my opinion, had had the wrong strategy.
"And take our gold portfolio, for example, the strategy for the last 10 or 20 years had always been based on this concept of self-funding to commercial production, and it's a strategy which I'd often seen up in North America and it rarely worked and where it did work, it took two to three times longer, because the situation is, is that whilst you generate a small amount of cashflow, it's generally barely enough money to keep the lights on, let alone fund any meaningful exploration.
"So for us, the big change when I came in was moving that mindset and that mentality away from small-scale production, and raising capital to fund aggressive exploration campaigns across the portfolio with the goal of defining a critical mass that we can then wrap a sustainable mine plan around for the next four to seven years."
The company resumed an aggressive exploration program at Burbanks last year, which has already resulted in two discoveries at Burbanks South and Burbanks North.
Drilling at Burbanks South returned results including 12m at 4.51 grams per tonne gold from 50m, including 6m at 7.28gpt, while 3.1m at 11.72gpt gold from 282.4m, including 1.1m at 29.48gpt and 0.3m at 89.7gpt was hit at Burbanks North.
Burbanks North has subsequently returned bonanza-grade intersections including 5m at 30.46gpt gold from 292.1m, including 1.3m at 97.28gpt gold.
"We've grown that mineralised strike horizon from around 1.5km to in excess of 3-3.5km and we've still got, I would say, 10 or 15, targets around that immediate Burbanks area, which require testing and further follow-up," Hansen said.
"What we're looking to do is undertake an interim resource update, just to take stock of the work that we have been doing out there over the past 6-8 months, and give the market a bit of an update and guidance in terms of what they can expect going forward as well."
Greenstone has also enjoyed a share price boost in recent months due to Galileo Mining's Callisto palladium discovery, which is just 200m from the boundary of the Mt Thirsty JV.
The JV will kick off an initial 5000m program to test the potential in early August.
"The size and the scale and the monster of a geological system, like Brad [Underwood] and the Galileo team think it is, we hope, based on our geological interpretations, that geophysics is continuous, bedrock is continuous, and we're very eager to test that early next month," Hansen said.
"So over the past eight weeks, we've worked incredibly hard to expedite that exploration program down there, to the point we've negotiated and executed an updated heritage agreement with the Ngadju, we've completed the heritage survey last week, secured a drill rig, additional field staff, PoW applications.
"I think, in this current market, to do all of that inside eight weeks, it's a reflection of us as a management team and how quickly we're looking to accelerate and unlock the value from this portfolio."
As well as the new name, Greenstone's rejuvenation under Hansen has also included a new board.
Geologist Mike Edwards joined as chairman, while fellow geologist Glen Poole joined as a non-executive director.
"Mike has been absolutely fantastic. Him and I think very alike in terms of my being a geologist by trade, but importantly, he's spent a long time within public equity markets as well which has complimented my skills very nicely," Hansen said.
"And Glen Poole has just been absolutely invaluable to unlocking the value, particularly within that gold portfolio. Glen was previously with Northern Star and worked across a number of their operations, importantly for us, worked at the Kundana operations, which is really the closest geological analog to what we're dealing with at Burbanks."
A chance encounter at university got Hansen into geology. He'd initially studied business but quickly realised it wasn't for him.
Hansen said his perception of geology had been "socks and sandals" and working for the government.
He described a "very fortuitous" encounter with a geology student at the university bar, who explained Western Australia's booming mining sector and the sort of money graduates were getting paid.
The penny dropped and Hansen switched subjects.
He initially worked for Northern Star in the Goldfields, then moved to iron ore in the Pilbara with Fortescue Metals Group.
Hansen completed a masters of mineral economics in the background and made the move to London, where he scored the job with Appian.
"I based out of London for five years and ultimately was VP of investment," he said.
"At that time, we had a fund of around $US350 million that we deployed across a handful of mining opportunities."
Hansen and his wife returned to Perth for family reasons just before the start of the pandemic.
"Since returning to Australia, I was business development manager for Andrew Forrest's private minerals and mining portfolio, Wyloo Metals, and during that time, led several transactions, most notably the circa $30 million stake in Noront Resources, which ultimately triggered a very public takeover battle between Andrew and BHP for the remainder of the company."
Hansen has been lucky enough to travel the world in his private equity roles but his current role is better suited to his young family.
He's got two young daughters, one who is three-and-a-half and the other six months old.
"They both they both consume a lot of time and I say that in the nicest possible sense," Hansen said.
"They're both beautiful young girls but I think being a director of a publicly listed company and managing a young family comes with its own host of, I guess, difficulties and issues that you have to manage."
Chris Hansen is a nominee for Emerging Leader of the Year in the 2022 MNN Awards.
