BE MINCOOL - COLLECT. LEARN. DISCOVER.

World
Tumbled Stone Collection

Embark on a journey around the world without ever leaving home. This unique collection of rough stones from various parts of the globe will reveal the geological richness of our planet. Each stone in this set is a small piece of the Earth, and each one tells its own story.

ROCK CRYSTAL (Brazil)

  • Characteristics: Rock crystal is a transparent and clear variety of quartz, representing one of the purest forms of silicon dioxide. It is distinguished by its glassy luster, high hardness (grade 7 on the Mohs scale), and exceptional durability. Due to its piezoelectric properties, it has a wide range of uses in many industrial fields and in jewelry making.
  • Formation: It is formed by the long-term crystallization of silica from hot aqueous solutions inside rock cavities, often in so-called hydrothermal veins. The crystals can grow for millions of years.
  • Occurrence: Significant deposits are found in Brazil, the Alps (especially Switzerland), and the United States. In the Czech Republic, it is found, for example, in Moravia, specifically in the Vysočina region. Rare large crystals come from Madagascar. This particular stone comes from the state of Minas Gerais in Brazil.

ROSE QUARTZ (South Africa)

  • Characteristics: Rose quartz is a light to deep pink variety of quartz, which is often milky and cloudy. While it was previously thought that its color was due to the presence of manganese, more recent scientific studies have shown that the color is actually caused by fine inclusions of the mineral dumortierite. Rose quartz is very popular in jewelry and as a decorative stone.
  • Formation: It forms in the inner parts of pegmatite veins, where it slowly crystallizes from mineral solutions. The pink color of the stone can gradually fade due to sunlight.
  • Occurrence: Most rose quartz is mined in Brazil and Madagascar, but it also occurs in the USA, India, and the Czech Republic (for example, in the Vysočina region). This stone comes from mines on the border between Namibia and South Africa.

AMETHYST (Brazil)

  • Characteristics: Amethyst is a purple-colored variety of quartz. It owes its color to its iron content and the effects of natural radioactivity. It is a prized gemstone that was popular even in ancient times. Its shades range from a delicate light purple to a rich dark shade.
  • Formation: Amethyst crystallizes from hot solutions that penetrate into rock cavities, especially in volcanic environments. It often forms crystals on the walls of the cavities - the so-called amethyst geodes.
  • Occurrence: The most important deposits are found in Brazil (the Rio Grande region), as well as Uruguay, Russia (the Urals), Slovakia (Štiavnica), and the Czech Republic (Krušné hory). Our stone comes from mines near the city of Marabá in the Brazilian state of Pará.

AVENTRUINE (Zimbabwe)

  • Characteristics: Aventurine is a shimmering variety of fine-grained quartz that occurs in various colors, from red, yellow, and blue to green and brown. Most often, aventurine boasts a beautiful green hue, which is caused by a mixture of fine scales of chromian mica (fuchsite). The stone is characterized by a typical shiny appearance, known as aventurescence.
  • Formation: The stone is formed in metamorphic and pegmatite rocks, where tiny mineral particles penetrate into the quartz. It is these inclusions that give aventurine its specific color and sparkle.
  • Occurrence: High-quality aventurine is mainly mined in India, Russia, Brazil, and China. This stone comes from Zimbabwe.

SODALITE (Namibia)

  • Characteristics: Sodalite is a blue, sometimes blue-white or grayish-blue mineral, often confused with lapis lazuli. It is opaque with a waxy luster and is not very hard (reaching a hardness of 5.5–6 on the Mohs scale). It is widely used for the production of exclusive tiles and gigantic interior sculptures.
  • Formation: It is formed in alkaline igneous rocks, especially in syenites and nephelinites, where it is created during the cooling of magma with a low silica content.
  • Occurrence: Rich deposits are found in Canada (Ontario), Russia, Namibia, and Greenland. Our stone comes from mines in the Kaokoland region of Namibia.

VOLCANIC BRECCIA (Peru)

  • Characteristics: Volcanic breccia is a rock composed of fragments of volcanic rocks cemented together. It can contain a variety of colors and structures, which often gives it a "wild" look. Due to its unique appearance, it is popular for making jewelry and decorations.
  • Formation: The stone is formed during explosive volcanic activity - eruptions tear the rocks apart, which then mix with ash and lava. Under the influence of pressure and heat, this mixture gradually solidifies into a solid rock.
  • Occurrence: Volcanic breccias are associated with volcanic activity zones. Our stone comes from Peru.

TIGER’S EYE (South Africa)

  • Characteristics: Tiger's eye is a golden-brown variety of quartz with a silky luster and a unique optical phenomenon, the so-called "cat's eye effect." Its impressive appearance and shiny reflections make it a popular material for the production of exclusive figurines and jewelry.
  • Formation: The stone is formed by the alteration of the asbestos mineral crocidolite, which is gradually replaced by quartz. Its original fibrous structure is preserved, which causes the attractive optical effect.
  • Occurrence: The largest deposits are found in South Africa, as well as in Australia and the USA. This stone comes from mines near the town of Prieska in South Africa.

BLACK OBSIDIAN (Mexico)

  • Characteristics: Obsidian is a natural volcanic glass that is typically very dark to black in color. Although the stone is brittle, it has extremely sharp edges - which is why prehistoric people used it to make tools. The stone is characterized by a distinctive glassy luster.
  • Formation: Obsidian is formed in a unique way when acidic lava cools so rapidly that the individual minerals do not have time to crystallize.
  • Occurrence: Obsidian is found in areas with young volcanoes—Iceland, Mexico, Armenia, and the USA (Yellowstone). This stone comes from a volcanic area in the state of Jalisco in Mexico.

CARNELIAN (Botswana)

  • Characteristics: Carnelian is an orange-red variety of chalcedony (a fine-grained quartz). This translucent stone with a waxy luster owes its intense shades to the presence of iron oxide. Carnelian was very popular in ancient times and is still widely used in jewelry today.
  • Formation: The stone is formed in volcanic rocks and sediments, where silicon dioxide precipitates from solutions and is gradually colored by iron.
  • Occurrence: The largest carnelian deposits are found in India, Brazil, and Uruguay, as well as in the Czech Republic in the Podkrkonoší region. Our stone comes from Botswana.