Exploring the various gem and mineral shows in Tucson always has surprises in store, and this year was no exception, with a batch of fluorite specimens from Nigeria exhibited at the Pueblo show by Jigga Collins Mineraux (Sécheras, France). This new find of fluorite ranges in color from gray-blue to gray-green to bluish green under artificial light, shifting to violetish blue in sunlight (figure 1, left). Under natural lighting, most of the crystals show a bicolor effect created by obvious color zoning, with a green core highlighted by blue edges (figure 1, right). All specimens show strong fluorescence when exposed to long-wave (365 nm) UV light, turning to violet-blue or an intense electric blue color (figure 2).
The fluorite comes in clusters of euhedral, often twinned cubes ranging in size from 1 cm to more than 15 cm each, regularly associated with quartz, pyrite, galena, and calcite. Some of the crystals observed contained eye-visible fluid inclusions.
Nigeria is known for its variety of industrial and precious mineral resources, including some important fluorspar deposits. Collection-grade fluorite specimens were previously known from the Jos Plateau area, Benue state, and a few other localities (J.I. Omada et al., “The Kigom peralkaline granite pluton of the Nigerian Younger Granite suite,” Global Journal of Geological Sciences, Vol. 1, No. 1, 2003, pp. 1–12; S.O. Akande et al., “Minerology, fluid inclusion and genesis of the Arufu and Akwana Pb Zn F mineralization, middle Benue Trough, Nigeria,” Journal of African Earth Sciences (and the Middle East), Vol. 7, No. 1, 1988, pp. 167–180).
According to Collins, the exhibited mineral specimens come from a recently discovered deposit related to some areas of the Jalingo mine in the state of Taraba. The fluorite was located in 2022, and operations began in early 2023. Though the material had been introduced at the Sainte-Marie-aux-Mines Mineral & Gem Show (France) and at the Munich Show in 2023 (R. De Ascenção Guedes et al., “Une passion nommée Sainte-Marie-aux-Mines!,” Le Règne Minéral, No. 172, 2023, pp. 6–16; R. De Ascenção Guedes et al., “Munich 2023!,” Le Règne Minéral, No. 174, 2023, pp. 7–31), the Pueblo show was its North American debut.
Collins noted that some of the largest mined specimens reached 35–40 kg in weight and about 80 cm in height. While 3 to 5 tons have been mined so far, the use of improper tools and limited mining expertise led to excessive damage of the extracted material during the earliest operations, leaving top-quality specimens scarce. Mining operations have since improved and production remains seasonally active.
Exploring the various gem and mineral shows in Tucson always has surprises in store, and this year was no exception, with a batch of fluorite specimens from Nigeria exhibited at the Pueblo show by Jigga Collins Mineraux (Sécheras, France). This new find of fluorite ranges in color from gray-blue to gray-green to bluish green under artificial light, shifting to violetish blue in sunlight (figure 1, left). Under natural lighting, most of the crystals show a bicolor effect created by obvious color zoning, with a green core highlighted by blue edges (figure 1, right). All specimens show strong fluorescence when exposed to long-wave (365 nm) UV light, turning to violet-blue or an intense electric blue color (figure 2).
The fluorite comes in clusters of euhedral, often twinned cubes ranging in size from 1 cm to more than 15 cm each, regularly associated with quartz, pyrite, galena, and calcite. Some of the crystals observed contained eye-visible fluid inclusions.
Nigeria is known for its variety of industrial and precious mineral resources, including some important fluorspar deposits. Collection-grade fluorite specimens were previously known from the Jos Plateau area, Benue state, and a few other localities (J.I. Omada et al., “The Kigom peralkaline granite pluton of the Nigerian Younger Granite suite,” Global Journal of Geological Sciences, Vol. 1, No. 1, 2003, pp. 1–12; S.O. Akande et al., “Minerology, fluid inclusion and genesis of the Arufu and Akwana Pb Zn F mineralization, middle Benue Trough, Nigeria,” Journal of African Earth Sciences (and the Middle East), Vol. 7, No. 1, 1988, pp. 167–180).
According to Collins, the exhibited mineral specimens come from a recently discovered deposit related to some areas of the Jalingo mine in the state of Taraba. The fluorite was located in 2022, and operations began in early 2023. Though the material had been introduced at the Sainte-Marie-aux-Mines Mineral & Gem Show (France) and at the Munich Show in 2023 (R. De Ascenção Guedes et al., “Une passion nommée Sainte-Marie-aux-Mines!,” Le Règne Minéral, No. 172, 2023, pp. 6–16; R. De Ascenção Guedes et al., “Munich 2023!,” Le Règne Minéral, No. 174, 2023, pp. 7–31), the Pueblo show was its North American debut.
Collins noted that some of the largest mined specimens reached 35–40 kg in weight and about 80 cm in height. While 3 to 5 tons have been mined so far, the use of improper tools and limited mining expertise led to excessive damage of the extracted material during the earliest operations, leaving top-quality specimens scarce. Mining operations have since improved and production remains seasonally active.
