The institutions are headlined by EuroPac Gold Fund, while the initial placement of $5.4 million is being managed by California-headquartered Roth Capital.
New shares are being issued at a price of 12c each, with a share purchase plan seeking up to $2.5 million.
The raisings are being undertaken to fund the replacement Financial Assurance Bonds for the Texas silver project, the acquisition consideration for the Texas silver project and general working capital purposes.
Queensland-located Texas is the company's key project, with other exploration projects featuring silver, gold, copper and tin also located elsewhere in Queensland and New South Wales.
Shares in Thomson were down 7% to 13c in morning trade, capitalising the company at $44 million.
The stock was at levels around 2c in mid-2020.
