Chairman Andrew Bell defended the investment in the Australia-listed manganese producer saying it remains “an asset of the highest quality where we see unrecognised value and expect recovery."
Reported losses for the year to June were £22.1mln, which primarily consisted of the write-downs at Jupiter.
Elsewhere, Red Rock said it has met its objectives for the year with a resource estimate and pit and optimisation study at the MK gold prospect in Kenya and a resource for its Melville Bugt iron ore asset in Greenland.
Talks are still ongoing over the sale of a part of the stake in Greenland and also its gold mine assets in Colombia.
Red Rock added parent company borrowing had fallen to £800,000 post the end of the trading period. Future funding will largely be provided by asset sales and realisations.
Andrew Bell said: "Despite the market environment, we have continued to concentrate on developing Red Rock's portfolio of assets and enhancing value where we see opportunities within our focus on gold, iron ore and manganese.
"We believe that our approach has been validated through the offers we received in respect of our assets in Greenland and Colombia and will be working to progress these.
"We remain confident for the future and look forward to making further progress in the current financial year."
Shares edged higher to 0.71p.