PGM production from Hernic rose 18% quarter-on-quarter to 5,800 ounces, of which a record 2,100oz of PGMs were produced in a single month.
The strong production in turn helped the project's operational earnings jump 41% to £1.61 million (US$2.1 million) and project revenue increase 25% to £3.31 million.
The company's shares rose 6.66% Thursday on the results to 2.43p.
Jubilee CEO Leon Coetzer said the higher earnings reflected Hernic's low variable cost base per PGM ounce produced.
"The lower feed supplies which hampered production in June has been overcome and the project is poised to break through 6 000oz per quarter," he said.
At the DCM project in South Africa, chromite concentrate output came to 9,461 tonnes for the June quarter, slightly lower than the 9,810t produced the previous quarter.
Jubilee said it expected chrome production at DCM to remain at these levels while it built the project's fine chrome recovery plant, with the existing DCM material containing mostly fine chrome and enriched PGMs.
The company's overall project earnings for the quarter were up 31% to £1.65 million, including the £82,000 spent on plant refurbishment at DCM, while total project revenue rose 12% to £4.37 million.
In June, Jubilee started sending PGM material from its PlatCro platinum project to Northam Platinum's Eland Platinum operation, with 31,000t delivered during the month.
It started expanding PlatCro's material sorting and de-watering plant to support a targeted ramp-up of material delivery to 50,000t per month and build a stockpile of over 200,000t of PGM-rich material at the Eland Platinum concentrator prior to starting platinum recovery in February.
Jubilee has also started construction of the zinc recovery circuit at the Kabwe zinc-lead-vanadium project in Zambia as it concludes the design of the lead recovery circuit during the September quarter.