First gold production is planned for the end of 2019.
Richard Gray, chief executive, said: "We are delighted to have reached this point and are looking forward to a very exciting 2019, bringing the Cononish Project into production."
Scotgold expects to process around 3,000 tonnes of ore per month in the first phase, which will double in phase two.
A feasibility study last year estimated Cononish can generate between £67mln and £100mln in earnings over the life of the mine.
The pre-tax net present value was put at £43mln, using a 10% discount rate.
In early morning trading, Scotgold shares were 4.4% higher at 35.50p.
-- Adds share price --