Table of Contents

• Indiana’s Answer to the Subway Garnet by Chris Clemens 1–5
• Tucson 2024: Shows, Prospecting & More by Brian Walko 6–17
• Fuzzy Calcite from Polino, Italy by Simone Conti, Marco Costanzi, Michele Lustrino 18–21
• History and Nature of the “Cava dell’Oro” Site in Polino by — 22
• They “Glow in the Dark” – A Bright Green Sphere and a Blue Egg by Thierry Cathelineau 23–26
• Unexpected Gems by Rabbi Jeff Glickman 27
• Eye Candy from Tucson 2024 by — 28–31

Indiana’s Answer to the Subway Garnet

By Chris Clemens · pp. 1–5

A calcite crystal recovered during construction of Indianapolis’s DigIndy sewer tunnel offers a Midwestern counterpart to New York’s famous Subway Garnet. Collected from the Geneva Dolomite, the amber-yellow specimen has a distinctive pseudo-dodecahedral form and displays fluorescence and phosphorescence under short-, mid-, and long-wave ultraviolet light. The article recounts the tunnel project and the specimen’s discovery, compares its size and story with the almandine garnet, and describes the calcite’s optical response and dolomite matrix.

Tucson 2024: Shows, Prospecting & More

By Brian Walko · pp. 6–17

A trip to the 2024 Tucson mineral shows combines the Fluorescent Mineral Society meeting with collecting, museum visits, and regional sightseeing. The account covers Richard Graeme’s presentation on fluorescent minerals of Bisbee, night collecting in the Tombstone Hills, and a daytime visit to a Bureau of Land Management collecting area near Granite Gap. It also recounts visits to Tucson’s major shows and the Alfie Norville Gem & Mineral Museum, highlights fluorescent finds including calcite, aragonite, and hydrozincite, and describes the trip’s weather and excursions.

Fuzzy Calcite from Polino, Italy

By Simone Conti, Marco Costanzi, Michele Lustrino · pp. 18–21

Fluorescent calcite in volcanic rock from the Cava dell’Oro near Polino, Italy, provides a point of entry into a debate over the origin of the locality’s unusual carbonate-rich rocks. A collected specimen contains lapilli and carbonate cement, with small vugs holding calcite identified by Raman spectroscopy; the crystals show bluish-white fluorescence and greenish phosphorescence. The authors outline competing interpretations involving carbonatite magma or ultrabasic magma altered by limestone assimilation, arguing that available evidence leaves the petrological explanation unresolved.

History and Nature of the “Cava dell’Oro” Site in Polino

p. 22

The Cava dell’Oro in Polino, Umbria, is presented as both a historic mining site and an unusual geological locality. An English translation of the site’s information panel recounts 18th-century mining of iron and silver, with gold also reported in oral tradition, and describes the volcanic structures known as diatremes. Their breccias preserve material brought up from depth, while the rare kamafugite rocks of the Umbrian district make the outcrops of particular scientific interest.

They “Glow in the Dark” – A Bright Green Sphere and a Blue Egg

By Thierry Cathelineau · pp. 23–26

Two ornamental objects sold as a glowing sphere and egg are investigated through observation and spectroscopy. Grinding the sphere reveals that its luminous surface is a coating over a non-luminescent, dolomitic marble core, and Raman spectra confirm the dolomite. Photoluminescence measurements show green emission from the sphere and blue emission from the egg; the colors and long-lasting afterglow are attributed to strontium aluminate phosphors activated with europium, with additional dopants possible. The study distinguishes the decorative coating from the stone beneath it.

Unexpected Gems

By Rabbi Jeff Glickman · p. 27

Fluorescent minerals are presented as accessible prompts for curiosity, awe, and continued questioning rather than merely as specimens to identify. The author describes sharing rocks and ultraviolet lights with museums, teachers, and community members, and explains a donation project that distributes specimens of different sizes. Afghan newcomers are paid to make pendants from smaller stones, which are sold with compact lights to support the effort. The article also proposes arranging brightly responsive minerals in a rainbow display as a way to engage audiences and raise funds.

Eye Candy from Tucson 2024

pp. 28–31

A photographic gallery presents fluorescent mineral specimens and their localities, with images under visible and ultraviolet illumination. Featured material includes willemite, calcite, and dioptase from Gotala in the Republic of the Congo; sphalerite from Colorado’s Sweet Home Mine; plumbogummite with pyromorphite from China; and leucophanite from Mont Saint-Hilaire, Quebec. The gallery also shows calcite from Laie Quarry, Hawaii, and eucryptite from Xianghualing, China, documenting varied crystal forms and colors across the specimens.