The Blu Moon occurrence is located on the west side of the Slocan River, 2 kilometres northwest of the Blu Starr occurrence (MINFILE 082FNW259) on the Blu Starr gemstone property. The occurrence lies on the south-facing slopes of Perry Ridge, south of the community of Vallican. 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.
Sapphire mineralization at Blu Moon occurs as disseminations within syenite proximal to unmineralized feldspar-amphibolite dikes. Sapphires occur as hexagonal, barrel-shaped crystals and plates, either singly or in small groups. Colour is often zoned and ranges from sky-blue to cornflower and indigo blue, violet and purple.
The hostrock at Blu Moon is a calcareous biotite syenite gneiss intruded by feldspar and alkaline amphibole pegmatite sills and dikes. Magnetite is widespread in the syenite gneiss but absent in the sapphire-mineralized zone, where the syenite gneiss is tightly folded into a series of west-striking recumbent isoclinal folds. Related small thrust faults and fault breccias have developed parallel to the fold limbs and along adjacent gneissic layers. Sapphires occur in the hinge of the recumbent fold, directly above a pegmatite sill and within the metasomatic halo of the sill. The sapphire-mineralized zone is underlain by at least 10 metres of coarse feldspar-rich biotite syenite with scattered crystals of magnetite, pinky-green nepheline, large yellow-green apatite crystals and occasional veinlets and disseminations of translucent blue sodalite.
The Blu Starr sapphire deposit was discovered in 1991, followed by the discovery of the Blu Moon sapphire deposit 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 (Walker, 2012; 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. The sample consisted of approximately 20 tonnes of rock outcrop and 130 tonnes of greater than 7-centimetre-size rock screened from the talus slope below the sapphire outcrop. 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.
Anglo-Swiss Industries Inc. reported that United Radiant Applications of California had successfully heat treated 100 per cent of the initial test runs of rough sapphires to varying shades of blue. United Radiant will continue tests to determine the exact parameters of temperature, atmospheric conditions and time duration to maximize the percentage of gem-quality sapphires. Anglo Swiss sorted over 150 000 kilograms of bulk sample material for the extraction of sapphire crystals. Select hand-cobbed samples produced 10 to 200 carats per kilogram, including one rough crystal over 150 carats. The company is concentrating only on those crystals larger than 2 carats; to date it has recovered over 3000 carats of rough sapphires (T. Schroeter, personal communication, 1997).
The highest grade outcrops at the Blu Moon occurrence contain over 40 grams (200 carats) of sapphire per kilogram of rock (Walker, 2012). Previous hand mining and a 5-tonne bulk sample extracted in 1997 yielded an average of 1 kilogram (5000 carats) of coarse rough sapphire per tonne of rock (Assessment Report 26537).