The territory of Strandja Nature Park is endowed with many polymetallic deposits and ore reveals.
The ore mineral resources are presented by iron sulfide deposits, made of copper-polymetallic and copper-pyrite as well as titanium-iron ore layers, whose formation is associated with the introduction of the igneous rocks during the Upper Cretaceous series. The non-metalliferous mineral with the highest significance is the calcite marble from Malko Tarnovo, well-known since antiquity for their qualities.
The largest deposit on the Balkans of ancient metallurgical slags, which date back to V mil. BC is located in the Sguriite area, west of Rezovo village. Their quantity is estimated at around one hundred thousands tons. The deposits attests to an enormous for the Chalcolithic Age metallurgical activity associated with the most ancient civilization in Europe, which inhabited the coast of the Black Sea. The deposit near Rezovo, together with the Gramatikovsko ore field are one of the oldest mining centers in the world (4400-4200 BC). The gold in the ornaments at the eneolithic necropolis in Varna (Culture, Varna) has been obtained as metal precisely in Strandja.