This is Vivianite from Potosi, Bolivia at the Tucson Gem & Mineral Show. The mine was not specified. My daughter refers to this as the "Death Crystal" – a not entirely unearned moniker. (see below)[6]
www.mindat.org/locentries.php?p=14499&m=4194
www.mindat.org/locentry-11628.html
www.mindat.org/loc-351.html
Three small adits mined exclusively for vivianite specimens, located a few hundred meters downhill from the Canutillos mine (qv), to whose "Cooperativa" members it now belongs. Host rock is non-mineralized red argillaceous sandstone.
en.wikipedia.org/wiki/Vivianite
Bolivia: Llallagua, Potosi: Crystals to 10 cm at the Siglio XX mine.[5] Transparent bottle-green crystals to 10 cm from the San Jose/San Firmin vein. In general, the vivianite occurs as prismatic crystals on a matrix of botryoidal goethite derived from the alteration of pyrite and marcasite. Specimens found in 2000 were associated with childrenite, cronstedtite, pyrrhotite, franckeite and pink massive sphalerite.[17]
en.wikipedia.org/wiki/Vivianite
Vivianite (Fe(II)3(PO4)2·8H2O) is a hydrated iron(II) phosphate mineral found in a number of geological environments. Small amounts of manganese Mn2+, magnesium Mg2+, and calcium Ca2+ may substitute for iron Fe2+ in its structure.[5] Pure vivianite is colorless, but the mineral oxidizes very easily, changing the color, and it is usually found as deep blue to deep bluish green prismatic to flattened crystals. Vivianite crystals are often found inside fossil shells, such as those of bivalves and gastropods, or attached to fossil bone. Vivianite can also appear on the iron coffins or on the corpses of humans as a result of a chemical reaction of the decomposing body with the iron enclosure.[6]
It was named by Abraham Gottlob Werner, the "father of German geology", in 1817, the year of his death, after either John Henry Vivian (1785–1855), a Welsh-Cornish politician, mine owner and mineralogist living in Truro, Cornwall, England, or after Jeffrey G. Vivian, an English mineralogist.[7] Vivianite was discovered at Wheal Kind, in St Agnes, Cornwall.[3]
www.visittucson.org/tucson-gem-mineral-fossil-showcase/
"Every year the world-renowned Tucson Gem, Mineral & Fossil Showcase is like a time portal, a trip around the world, and a treasure hunt all rolled into one. Every winter, more than 65,000 guests from around the globe descend upon Tucson, AZ, to buy, sell, trade, and bear witness to rare and enchanting gems, minerals, and fossils at more than 50 gem show locations across the city. If you’re planning a winter visit to Tucson, you won’t want to miss this three-week-long event filled with shows, related events, a free day at the gem & mineral museum, and much, much more!
"Whether you’re looking for a $5 shimmering crystal necklace or a show-stopping $200,000 crystallized rock from an exotic location, the Tucson Gem, Mineral, & Fossil Shows have something for everyone."
www.visittucson.org/blog/post/gems-and-minerals/
www.tgms.org/show
The theme this year was Shades of Green- Experience the Magic. The theme for next year’s show will be Red, White, and Blue Celebrate the Spirit of Minerals
xpopress.com/news/article/783/shades-of-green-70th-annual…
TGMS 2025
Tucson Gem Show 2025
Posted by Al_HikesAZ on 2025-03-13 00:41:25
Tagged: , 2025 , 71st , AZ , Al_hikesaz , Arizona , Bolivia , Center , Convention , Earth Science Teaching Resource , Gem , Mineral , Potosi , Rock , Show , Showcase , TGMS 2025 , Tucson , Tucson Convention Center , Tucson Gem Show , Tucson Gem and Mineral Show , Tucson Rock Show , Vivianite , death crystal , fossil , rocks
