The Tedesco Garnet occurrence is found on the Blu Starr gemstone property and reached through a series of logging roads westward from Passmore and Vallican along the Little Slocan River to Perry Ridge. The Blu Starr property is situated at the confluence of the Slocan and Little Slocan rivers near Passmore, approximately 25 kilometres west of Nelson.
The Slocan Blu Starr property lies within the southern portion of the Valhalla-Passmore Gneiss Complex, in the Passmore Dome. The Valhalla Complex consists of a high-grade metamorphic core with outwardly dipping metamorphic layering and foliation. Heterogeneous sequences of biotitic schist (pelitic schist), quartzo-feldspathic gneiss (psammitic gneiss), amphibolite gneiss and minor marble, calc-silicate gneiss, quartzite, metaconglomerate and ultramafic rocks make up the Valhalla assemblage of metamorphic rocks. The Tesdesco area geological units cannot be directly correlated with other areas of the Slocan Blu Starr property. The area hosts distinctive graphite marbles that are not known to occur on other areas of the property.
The Tedesco garnets are almandine-pyrope garnets of unknown proportions with an intense fiery red colour. Garnet occurs in the hostrock as irregularly distributed single crystals up to 10 centimetres in diameter and crystalline masses up to 30 centimetres wide. Large garnet crystals sometimes display a regrowth of garnet in a parasitic internal crystal of the same colour, which is often more transparent than the host garnet. Based on bulk sample results, the average weight content of the hostrock is 10 per cent garnet (Press Release, Anglo Swiss Resources Inc., December 18, 2012).
A flat-lying garnet-bearing pegmatite sill, 30 to 50 centimetres thick, is exposed for 30 metres along a logging road. Hand trenching indicates the sill is at least 4 metres wide. The sill remains open in all directions. Minor graphite, pyrite and chalcopyrite are locally present within the pegmatite hostrock.
The Blu Starr sapphire deposit was discovered in 1991, followed by the discovery of the Blu Moon sapphire deposit (MINFILE 082FNW263) to the northwest in 1993. From 1991 to 1995, approximately 10 tonnes of sapphire-bearing rock was hand mined, yielding approximately 10 kilograms (50 000 carats) of coarse rough sapphire from Blu Starr and 1 kilogram (5000 carats) from Blu Moon (Press Release, Anglo Swiss Resources Inc., December 18, 2012). The property was acquired by Anglo Swiss Resources Inc. in 1995. That same year, Marylou Coyle, PhD, was contracted to study the deposits and make recommendations for development. In 1996, the first organized geological studies of sapphire deposits were conducted, leading to the discovery of aquamarine beryl crystals in quartz-tourmaline pegmatitic dikes. In 1997, a 150-tonne composite bulk sample was extracted from the Blu Moon deposit and sent for processing. Smaller hand samples were taken from Blu Starr and other gem showings on the property. In 1998, a small gem garnet deposit was discovered on a mountainside near the Blu Starr deposit and a 2-tonne bulk sample was extracted. That same year, an extensive mineralized zone of crystalline graphite was discovered in the Tedesco area and the Sapphire Hill occurrences were found near the Blu Moon deposit. Three zones of iolite mineralization were also found north of the Blu Starr deposit in the fall of 1998. One tonne of sapphire-mineralized rock was extracted from Sapphire Hill and two 1-tonne bulk samples containing approximately 25 kilograms of coarse rough crystal and gem iolite were extracted from the I1 and I2 iolite zones. In 1999, a detailed geological examination of the iolite zones was completed.
In 2000, Hampton Court Resources partnered with Anglo Swiss Resources in a joint venture. Exploration by Hampton Court focused on evaluating the potential of placer claims along the Slocan River, west of the Blu Starr deposit. The potential of alluvial deposits along the Slocan Valley was assessed with respect to potentially commercial deposits of gemstones, including garnet, iolite and sapphire. Work that year consisted of 8.5 kilometres of ground-penetrating radar, surface geological mapping and preparation of a report titled Mineralogic Evaluation of the Slocan River Placer Claims. At the same time, exploration continued on other areas of the property. Thirteen new sapphire occurrences were identified, as were occurrences of amethyst quartz, rose quartz and titanite. Ten new iolite-anthophyllite occurrences were discovered along the Rainbow Horizon, and the New Star claim was staked to cover the northern extension of the iolite-anthophyllite–bearing Rainbow Horizon. A potentially large and economic gem garnet occurrence was identified in the Tedesco area. Bulk samples were extracted from the Tedesco garnet deposit (2.76 tonnes) and the I1 Iolite deposit (greater than 100 tonnes). More than 1000 carats of red garnet gem rough were recovered from Tedesco and more than 5 tonnes of specimen crystal and coarse rough gem material were recovered from the I1 Iolite (Assessment Report 26537).
In 2003, the joint venture with Hampton Court lapsed. Work on the property was suspended until 2008, when a graphite exploration program was undertaken. Ground geophysics was used to explore for graphite up to 200 metres in depth. Three diamond drillholes totalling 812.9 metres were completed. In 2010, 525.9 kilometres of airborne geophysical surveys were completed across the entire property. A limited ground survey of soil sampling and prospecting was carried out on the region of known graphite occurrences. In 2012, an induced polarization survey was carried out over the Tedesco graphite showing.
