Chinese Name： 螢光方鈉石 / 優伯石/ 正長岩/火焰石
English Name： Yooperlite / Syenite rock
Optical Effect：Fluorescence under UV
Chemical: Syenites comprise a slight amount of silica, incredibly big amounts of alkalies, and alumina.
Syenite：Syenite’s name comes from Syene, Egypt, the place where this type of rock was first discovered and classified by ancient Roman naturalist Pliny the Elder.Syenite is a coarse-grained intrusive igneous rock with a general composition similar to that of granite, but deficient in quartz, which, if present at all, occurs in relatively small concentrations (< 5%). 
Syenite is intrusive igneous rock that basically composed of an alkali feldspar and a ferromagnesian mineral. A unique group of alkali syenites is characterized by the presence of a feldspathoid mineral inclusive of nepheline, leucite, cancrinite, or sodalite.
Hardness：5.5 - 6.0
SG：~ 2.7
Locality：Michigan
Colour：To the naked eye, they look like gray rocks, but under the UV light, the mineral composite makes the rocks glow.
Background：Recently discovered by Erik Rintamaki, Yooperlite rocks are actually Syenite rocks that are rich in fluorescent Sodalite
In 2017, Erik went out on a beach in Lake Superior with a UV light and discovered dozens of these glowing rocks. To the naked eye, they look like gray rocks, but under the UV light, the mineral composite makes the rocks glow.