Jeremejevite is a rare aluminum borate mineral. In 1883, colorless crystals were first identified on Mt. Soktuj, in the Adun-Chilon Mountains of Siberia, Russia. It was named after Russian mineralogist and crystallographer, Pavel Vladimirovich Eremeev (Jeremejev, in German). A second occurrence of jeremejevite, blue crystals first believed to be aquamarine, was found in 1973 in Namibia. It has also been found in Tajikistan, Germany, Madagascar and Burma. Jeremejevite is most often found as colorless, white, pale yellow or blue crystals. Typically found in small sizes, jeremejevite is a valuable collector’s gem. This oval cut jeremejevite from a 2001 find in the Erongo Mountains of Namibia weighs 11.30 carats. This gem is very rare because of its large size and blue color. It is a major upgrade as it is the largest blue jeremejevite gem in the National Gem Collection from Namibia.