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About Us
Mineralia Tibi - minerals for you
In our online store, you will find carefully selected collector’s mineral specimens from verified localities and reliable suppliers. We focus on quality, authenticity, and fair pricing – instead of jewelry or costume pieces, we offer original natural specimens.
The project is primarily led by Jakub “Jeff” Ptáček, a geology student and long-time mineral collector, whose passion for stones began during childhood expeditions. His father, Václav, who has also been involved in collecting since his youth, contributes to the online store as well.
Our goal is to make the beauty of minerals accessible to everyone who wishes to admire, collect, or gift them. In addition to sales, we also offer to buy your collection or some basic stone processing (cutting and polishing).
Další zajímavé informace o nás se můžete dozvědět třeba zde
Fotografie z rýžování zlata
Základní vysvětlivky
Key Terms
Crystal system
A crystal system refers to the fundamental way in which atoms are arranged within a crystal. This arrangement determines the shape and symmetry of crystals based on their axes and the angles between them. All crystalline substances are classified according to the symmetry of their crystal lattice into one of the seven crystal systems.
Types of crystal systems:
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Triclinic
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Monoclinic
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Orthorhombic / Rhombic
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Tetragonal
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Hexagonal
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Trigonal
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Cubic
Cubic system
Mineral hardness
Mineral hardness is, simply put, the ability of a mineral to resist scratching by another mineral or material. It is measured on the Mohs scale of hardness, which is based on the principle that a harder mineral will scratch a softer one. There are ten levels of hardness, with 1 being the softest mineral and 10 being the hardest. The differences in hardness between each level vary, with the greatest difference occurring between levels 9 and 10.
Common tools with known hardness are used to determine a mineral’s hardness:
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Up to about level 2, a mineral can be scratched with a fingernail.
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Up to about level 3, it can be scratched with a copper plate or coin.
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Levels 4–5 can be scratched with an iron nail.
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Up to about 5.5, a mineral can be scratched with a glass plate.
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Up to about 6.5, a mineral can be scratched with a steel file.
For harder minerals, hardness is determined by scratching them with even harder minerals (for example, corundum can scratch everything except diamond).
(Mohs scale of hardness)
Density
Density indicates how much mass is contained within a given volume. In other words, the higher the density, the heavier the object is.
For minerals, density is commonly expressed in g/cm³ and mainly depends on the chemical composition and the structure of the crystal lattice.
For example, a pyrite crystal (cube) with a 2 cm edge and a density of 5.1 g/cm³ would weigh approximately 40 g, whereas a gold cube of the same size (19.3 g/cm³) would weigh around 150 g.
Density is frequently used in mineral collecting, particularly for panning (gravity separation) of gold, garnets, sapphires, and other heavy minerals.
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