• Location: Brehov, Slovakia
• Total Weight: 250g
• Weight Range: 5 - 23 g
• DETAILED DESCRIPTION

Obsidian from Eastern Slovakia General Obsidian is a type of volcanic glass, a rock that forms as a result of magmatic activity when incandescent lava rapidly comes into contact with a cold environment and solidifies quickly. The rock is very rich in silica compounds and is a natural form of glass. It is typically dark in color, varying from black to gray or red. It is generally opaque, but its transparency increases as the iron oxide content decreases. History The presence of obsidian in Slovakia is relatively limited compared to other local neo-volcanites. Our ancestors used it to produce cutting tools as early as the Paleolithic (2,500,000 years ago), but it has been shown that these tools were also used in the Neolithic (5,000 years ago). In Europe, there is only a limited number of primary obsidian deposits suitable for the production of sharp tools, especially scrapers, spearheads, or knives. From the results of ongoing research, it is clear that the importance of eastern Slovakian obsidian as a raw material for the production of chipped tools far exceeded its local significance. For this reason, eastern Slovakian obsidian was distributed throughout Central and Eastern Europe and across the Balkans to the Mediterranean. A little chemistry Obsidian is the product of highly acidic lavas of Neogene volcanism. Its origin is closely linked to rhyolitic volcanism. Its deposits form the peripheral parts of large volcanic bodies composed mainly of rhyolite. Obsidian nodules, mistakenly called "mounds" by collectors, are generally found in rhyolitic tuffs, from which they have often been freed by erosion due to their greater resistance; for this reason, their shape and surface often resemble Bohemian moldavite. Eastern Slovakian obsidian belongs to the group of unaltered acidic volcanic glasses with a silica (SiO₂) content of about 80%. The higher acidity of local lavas resulted in a higher SiO₂ content and lower water content in obsidians compared to the world average. This is the reason for their greater durability and suitability for the production of chipped tools. The water content of obsidian is unusually low. The H₂O content varies between 0.19 and 0.31%. The density varies between 2.3 and 2.4 g/cm³. Porosity is well below 1% and hardness is between 5 and 5.5 on the Mohs scale. Local obsidian is transparent. Depending on the chemical composition, its colors vary from black to gray, to bluish and greenish hues, sometimes with silvery reflections. No other obsidian in the world offers such a range of colors! Curiosities / Potential By a surprising coincidence, the presence of obsidian in Slovakia dates back about 15 million years, more or less the same period as its Czech "sister," moldavite, to which it is often compared in appearance. At a certain distance and with the right lighting, the two stones can appear indistinguishable. Of course, upon closer inspection, the differences become evident and they cannot be confused. Interest in obsidians in general is growing both in Europe and the rest of the world. Slovakian ones are valued for their rarity, limited quantity, unique color, and resemblance to moldavite. Their current low price makes them an ideal stone for future value appreciation. Obsidian is easy to work with and polish, and as a raw material, it is truly suitable for jewelry and crafts. It is also used to make replicas of Paleolithic tools, stone beads, and jewelry. Obsidian can be collected at various sites in the form of small pebbles from 1 to about 20 cm in diameter. However, most nodules measure between 1 and 5 cm. Their predominant color is black or gray-black. Cut stones achieve a high polish, and the cutting yield is comparable to that of commercial colored chalcedonies. It can be used not only in the form of simple cabochons or tables, but, being transparent, it can also be faceted with round and step cuts. Faceted stones are very spectacular and surpass dark gneisses and morions in appearance. Due to its easy workability, it is also a suitable material for plastic carving of small figures, the so-called glyptics. In any case, it deserves to be promoted as one of the most interesting materials used since the Stone Age. Although interest in natural glass mainly grows thanks to tektites, other forms are also increasingly mentioned alongside them. The scientific community has organized several conferences dedicated to research on natural glasses. In 1987, one of these took place under the patronage of Charles University in Prague. For this conference, the Granat Turnov cooperative produced silver jewelry whose main stone was precisely obsidian from eastern Slovakia. Requests and orders from abroad continued for several years. Uses of Obsidian Obsidian has a wide range of uses due to its physical and aesthetic properties. Tools: Historically, obsidian was widely used to make various tools and weapons, especially in prehistory. The sharp edges of obsidian were ideal for creating: Arrowheads and spearheads: Due to its sharpness and hardness, obsidian was an ideal material for arrowheads and spearheads. Knives and scrapers: It was used to produce essential cutting tools for the daily life of prehistoric man. Jewelry and decorative objects: Due to its luster and aesthetic qualities, Slovak obsidian is a highly valued material for making jewelry and decorative objects: Necklaces, bracelets, and rings: Obsidian is often used in jewelry to create various types of ornaments. Amulets and talismans: Due to its beauty and supposed protective properties, obsidian is often made into amulets and talismans. Decorative figurines and artistic objects: Obsidian crafts are appreciated for their aesthetic and artistic qualities. Healing and esotericism: Obsidian is often associated with spiritual and therapeutic practices: Protective properties: Some people believe that obsidian has the ability to ward off negative energies and protect the wearer from psychic attacks. Healing: In alternative medicine, obsidian is used for its supposed ability to promote emotional balance and inner healing. Collecting: Mineralogical collections: Obsidian is very popular among mineral and gemstone collectors who appreciate its unique properties and appearance. Modern medicine: Surgical scalpels: Although less common, some surgical scalpels are made of obsidian because their extremely sharp edges allow for very precise incisions. Sculpture: Sculpture and carving: Artists use obsidian to create detailed sculptures and carvings due to its excellent workability.