Why was gold kept a secret by the government before the 1850s?
Gold was discovered in Australia as early as 1823, but discoveries were kept secret for a number of reasons.
First, there was the fear of sparking off unrest among the convicts. There was concern that, if the convicts heard about these discoveries, they would be more likely to attempt escape, and find their way to the goldfields to either look for gold, or to become bushrangers. This is why the first unofficial discovery of gold by Surveyor James McBrien at the Fish River near Bathurst, NSW in 1823, was kept quiet. When Reverend WB Clark found gold near Lithgow in 1941, he was requested by Governor Gipps to keep quiet about it. Gipps is reported to have said, "Put it away, Mr Clarke, or we will all have our throats cut!"
The discoveries were often made on good land. Settlers did not want a sudden influx of prospectors trooping over their properties, ruining good pastureland for their livestock, or damaging crops. They certainly did not want to risk the lawlessness that would inevitably follow. Not did they want their workers leaving in droves to find gold.
Prior to 1851, any gold discoveries automatically belonged to the government. There was no motivation for individuals to go out and actively seek gold, and certainly no motivation for them to make these discoveries public.