Personal collections of minerals, gems and fossils are being exhibited by some 60 participants. "Everyone can find what they are looking for at our exhibition," said Svetla Stariradeva, chief curator at the Earth and People Museum, giving an example of how a visitor came across an interesting mineral that changed colour: "Here we came across exactly those exhibits where the mineral changes colour, when it is not illuminated it is dark, and when the person brought it into stronger light it changed colour and turned purple. In a short time, many specimens were bought. Our museum bought such a specimen. It is from Great Britain," Svetla Stariradeva explains. 

According to her, the amethyst is one of the emblems of the museum. "In fact, it is the most attractive variety of quartz and many women in Bulgaria own such jewellery - the more purple the colour, the more valuable it is," said Svetla Stariranjeva, adding that the exhibition included crystals from Brazil and Uruguay, but also from Bulgaria.