A number of magnetite skarns lie within, or adjacent to, the outcrops of the Housetop, Ringwood and Kara granites. Turner (1989) lists magnetite skarns at Kara No I, Kara No 2, Sutton's, Hampshire (near the railway crossing), Redwater Creek, Laurel Creek and Peak Hill Farm. In the past, these magnetite bodies were worked sporadically as sources of iron for steel making, for example, at Pearson's workings in the Kara No 2 Main deposit. Some of the magnetite skarns contain economic concentrations of scheelite, for example Kara No 1, Eastern Ridge, Bob’s Bonanza, Location 5 and Kara 266.

Several scheelite-magnetite skarns occur on the Kara mine lease. The skarns are developed within folded Ordovician limestone rocks which are in contact with Devonian granite.

"Several scheelite-bearing garnet-diopside magnetite-amphibole- vesuvianite skarns have formed at a transitional boundary between siliceous sandstone and quartzwacke (Moina Sandstone) and overlying Gordon Group limestone. Most deposits are within a synformal structure in the Ordovician sedimentary rocks which are underlain and intruded by porphyritic and equigranular biotite-hornblende granite of the magnetite-series of the Devonian Housetop Granite.

The main deposits are within a trough-like pendant of skarn within the Housetop Granite. At Kara No.1 ore-grade scheelite mineralisation forms an irregularly-shaped blanket draped 15 25 m above the granite. Between the skarn and the granite is a tungsten-poor, quartz-epidote reaction zone. Skarn lithologies are varied but there is a sharp division between magnetite dominant and garnet (grossular-andradite) dominant units.

In 2015 the Tasmania Mines operation reported production of 386,462 dry tonnes of magnetite ore from the Kara No 1 open cut. Mining operations currently consist of the mechanised excavation of weathered (oxidised) ore and overburden and blasting of fresh ore and waste rock with production blast holes - all mining operations are conducted by contract operators. Waste produced is currently utilised in tailings dam construction or placed within permanent waste storage facilities.

The current operating pit, the Stage 1 pit design, was generated and scheduled to supply high grade magnetite whilst conducting waste stripping for a Stage 2 pit. A concept of pit extensions (40m northward increments) was subsequently introduced and scheduled to maintain long term pit ore supply.

The extraction process for magnetite utilised
gravity and magnetic separation to produce 189,935 tonnes of magnetite concentrate during 2015. Water used in the process is recirculated wherever it is viable to re-use it. The processing operations are conducted by operators employed directly by Tasmania Mines.

Scheelite concentrate continues to be intermittently produced. The process for scheelite recovery historically used gravity concentration on tables, sulphide cleaning by flotation and the removal of iron compounds by roasting and magnetic separation. Development and commissioning of a scheelite flotation circuit continues – current gravity recoveries, when operating, remain at low levels. Data for flotation recovery is not available.

Tasmania Mines produces scheelite of a single grade defined by the tungsten oxide content. High grade concentrate contains approximately 73% W03.