Calcite with Boulangerite inclusions from Herja Mine, Baia Mare, Maramureș County, Romania. A striking specimen of calcite with fine boulangerite inclusions from the classic Herja Mine, Baia Mare, Maramureș County, Romania. Delicate, fibrous boulangerite is enclosed within the translucent calcite crystals, giving them an attractive smoky to silvery internal pattern and excellent visual depth under good lighting. This piece is a characteristic example of the famous Herja ore deposit, highly desirable for collectors of Romanian sulfide–carbonate associations and elegant display minerals. Herja Mine is celebrated among collectors for producing classic replacement minerals and unusual pseudomorphoses, including sphalerite after pyrrhotite, a combination highly valued for its scientific interest and visual appeal. This specimen represents both the exceptional geological processes and rich collecting culture of Baia Mare, making it a must-have for enthusiasts of transformation mineralogy and Romanian mining heritage. The Herja Mine in Baia Mare, Maramureș County, Romania stopped operating permanently in 2005 along with all major mines in the region. After closure, the workings were left without maintenance and have since been reclaimed by nature.