What are stones with crystals called?

“Contemplation of crystals sharpens the mind and elevates the soul.” “Stones are silent teachers, they make those who observe them silent, and the best that can be learned from them cannot be communicated to another.” “. Every stone is given its own. The native stone, in which the joy of the Earth is collected, makes spring in the heart, gives joy to a person.” (P.P. Bazhov “Malachite Box”) What do we know about crystals? For some, crystals are associated with a museum rarity, and for others – with a magical mystery. In fact, both sides will be partly right. But everything is in order. Among all the variety of natural artifacts, the world of stones and minerals has the greatest variety of colors and shapes. Solid construction contrasts with visual fragility, and complex geometry with perfect symmetry. Nature is the best sculptor, endowing the objects around us with indescribable beauty. Like each of us, crystals have individuality – appearance and character. Many of them are endowed with a bizarre shape, be it a galena druse, shimmering quartz, or an entire galaxy inside an agate geode. Therefore, crystals, like treasures, become desirable objects for collectors and connoisseurs of beauty.

From history.

In ancient times, only one mineral was called a crystal – transparent quartz (other names: rock crystal, Arabic diamond, Bohemian diamond). Due to its transparency and glassy sheen, the Greeks named it “krystallos”, which means “ice”. Along with pearls and amber, rock crystal was one of the most popular talismans – vessels and cups, dishes and mirrors, fortune-telling balls and jewelry were made from it. Even then, crystal was considered something divine and magnetic, captivating the minds of representatives of various walks of life. Only in the 17th century did the first scientific views on the nature of crystals begin to take shape, including the theory of the “brick” structure. Thanks to the advent of X-rays at the beginning of the 20th century, the idea of ​​the presence of a spatial lattice was confirmed, and wide possibilities for the use of crystals in human life opened up.

What is a crystal?

Crystals are not only minerals and gems that the earth’s crust is rich in. They surround us everywhere, and many common substances for us are crystals (ice, salt, sugar, etc.). Sand and granite, amber and topaz are all crystalline bodies. If you look at a grain of sand or salt through a microscope, you can see many perfect crystals. They, in turn, consist of organically located particles. Amazing symmetry is a consequence of an ordered structure, or more precisely, a perfectly organized lattice of atoms, molecules and ions.

Ideal shaped octahedron diamond.

Thus, crystals are solids that have the natural shape of regular polyhedra. They are formed from melt, solution and gas. In nature you can often find minerals consisting of many single crystals. Large homogeneous crystals are rare. How does the crystallization process occur? Let’s imagine that parquet is being laid in a large room. Anyone who has done renovation work knows that it is better to choose square tiles. This makes it easier and faster to work. In this way, crystallization of compounds consisting of their atoms or symmetrical molecules occurs. If you take a tile of a non-standard shape, with protrusions and irregularities, then the correct pattern may not work out. During installation, voids may arise, which will lead to inconsistencies. An interesting fact remains that the uneven edges of the crystal grow and change much more slowly than the “correct” ones. So, even if the vertices of the crystal are damaged, its edges and faces will develop according to the original shape. During the crystallization process, each particle fits not in a plane, but in a volume. The process of “searching for a place” is carried out due to thermal movements towards an energetically favorable location. This is how the individual shape of the crystal is formed. For some bodies it is static. For example, for sodium chloride this shape is a cube, for pyrites it is a pentagon dodecahedron.

Crystal sizes.

Natural crystals can vary in size: from huge to microscopic. For example, in one of the corners of the Republic of Buryatia a smoky quartz crystal weighing about 70 tons was found, and in the Baikal region valuable lapis lazuli crystals only 2 centimeters long were discovered. The appearance of the same mineral can vary depending on how it grew. Most crystals in nature grow over centuries. However, there are exceptions – crystals of rock (table) salt and copper, sugar and potassium alum. Such specimens can also be grown at home.

Copper sulfate crystals grown at home.

Unfortunately, crystals can not only form and grow, but also disappear – dissolve, melt and even evaporate. Disappearance occurs as slowly as appearance. The unsaturation of the surrounding solution and the emergence of active reagents affect the life of the mineral. There are impressive examples where water washes out kilometer-long caves, and all this is due to the high content of carbon dioxide in the liquid.

Properties of crystals.

Returning to the synonym for “mirror” crystals, it is worth mentioning another feature of crystals – refraction. The optical smoothness of the edges of most crystals gives a clear reflection of objects. Large crystals usually have imperfect edges due to irregular growth, so the reflection is often blurry. Therefore, miniature bodies are of greatest interest in the study of light refraction, namely in such a science as crystal morphology.

Druze.

Crystals nucleate on the substrate (base) in groups or individually. Fusing together, they form drusen. Druse (from German druse – “brush”) is a mineral aggregate of many tightly fused crystals. That is, each of the crystals of the group has an independent shape, and their general arrangement can be absolutely chaotic. The sizes and number of crystals on the substrate can be any. For example, drusen with low crystals (a few millimeters) is called a “brush”. And minerals that resemble buds in appearance, with crystals directed in different directions, are called “flowers.” Such formations fill the walls of voids, and are also found on open surfaces among rocks of igneous, metamorphic and sedimentary origin. Drusen often line the walls of cracks and also serve as filling for many geodes. Gemstones are often referred to as “crystals” and “minerals,” and the terms are considered interchangeable. However, we don’t even think about whether there is a difference between them? Today we’ll talk about the similarities and significant differences between crystals and minerals. In the photo: gems from the personal collection of Maxim Demidov. Minerals and crystals are natural formations that are closely related to each other. They are found both on the ground and in the lithosphere, underground cavities and geodes. The connection between them is essential – minerals are necessary for the formation of crystals. However, crystals, due to their chemical structure and long process of formation, are more complex than minerals. Let’s talk about them in more detail.

• Minerals are naturally occurring solids. They have very different chemical compositions, highly ordered atomic structures, and specific physical properties. Minerals are formed as a result of various geological processes and are more common in nature than crystals, since they are active crystal-forming compounds.
• Crystals are complex solid formations consisting of ions, atoms and molecules. They are born as a result of certain processes: chemical reactions, melting, cooling.

In the photo: mineral – zinc oxide under a microscope; crystal – zincite (formed from zinc oxide minerals).

How crystals form

Minerals play a significant role in the formation of crystals, acting as the “special ingredient”. Not only are they the building blocks for crystals, but they also form them under certain conditions. Under the influence of high temperatures, pressure, chemical reactions, deep underground, minerals and rocks are combined with each other. Over thousands of years, they slowly cool and turn into crystals. Thanks to mining, people find deposits of the most valuable precious stones, which were once just grains, but now can outshine everything around with their beauty.

In the photo: aquamarine and amethyst crystals.

In addition to underground crystals, there are also those that form on the surface of the earth. For example, some gemstones can be found in solidified volcanic rock. When a volcano erupts, molten magma flows into the mountain voids, cools and hardens. For thousands of years, chemical processes have been occurring inside this lava. Minerals, rock and volcanic rock particles are slowly transformed. Sparkling opal is a miracle born from such a union.

In the photo: a set with “Espectaculo” opals from the Maxim Demidov jewelry house.

Chemically, minerals may be the same, but form completely different crystals. There are different types of minerals found in nature:

• Silicates are the most widespread class of minerals in nature. Silicates make up about 75% of the mass of the earth’s crust and a third of all known minerals. These are silicon, oxygen, aluminum, iron, magnesium, manganese, calcium, sodium, potassium, lithium, boron, beryllium, hydrogen, zirconium, titanium, fluorine. Among the precious stones that are obtained from minerals of the silicate group: garnet, tourmaline, emerald, aquamarine, morganite.

In the photo: a set with polychrome tourmalines “Creative Classics” from the Maxim Demidov jewelry house.

• Halides are salts of hydrohalic acids. Their content in the earth’s crust is insignificant. The most famous halides are fluorite, rock salt and table salt.
• Carbonates are salts of carbonic acid. They make up up to 1,7% of the weight of the earth’s crust. The most famous carbonates are malachite, aragonite and calcite.

In the photo: mineral – calcium carbonate under a microscope; crystal – aragonite (formed from the combination of calcium carbonate minerals with other minerals).

• Oxides are minerals that are compounds of various elements with oxygen. They account for about 17% of the mass of the entire earth’s crust. Gems that are obtained from oxides: rock crystal, amethyst, citrine, ametrine, pink, milky and green quartz, aventurine, rauchtopaz, opal.

In the photo: ring with ametrine “Dominant of feelings” from the Maxim Demidov jewelry house.

• Sulfides are salts of hydrosulfide acid. They make up 0,25% of the mass of the earth’s crust. The most typical origin of sulfides is hydrothermal. They mainly serve as ore for the extraction of various chemical elements and are of great industrial importance. Among the most famous sulfides are pyrite, galena, bornite, and cinnabar.
• Sulfates are salts of sulfuric acid. They are lagoonal or lacustrine chemical sediments. Sulfates account for 0,1% of the mass of the earth’s crust. Sulfates form soft compounds such as: alabaster, gypsum, alunite, jarosite, celestine.
• Phosphates are salts of phosphoric acid. They make up no more than 0,1% of the earth’s crust. The main use of phosphates is as a raw material for the production of phosphate fertilizers, phosphorus, and phosphoric acid. Phosphates produce such a precious gem as apatite.

In the photo: ring with apatite “Unity with the World” from the Maxim Demidov jewelry house.

Differences between minerals and crystals

• The key difference between minerals and crystals is that minerals can only be natural substances, while crystals can only be natural and synthetic. For example, minerals are hematite, magnetite, quartz, etc., and a crystal can be artificial glass.
• Minerals are homogeneous solids with an ordered internal structure and are found in rocks, ores and mineral deposits in the earth’s crust. The crystal structure is defined geometrically. The crystal lattice contains compounds and formations consisting of minerals and grows according to certain rules of symmetry – syngony. It can be triclinic, monoclinic, rhombic, tetragonal, trigonal, hexagonal and cubic. When studying precious stones, gemologists indicate the syngony or type – which symmetry class the crystal belongs to.

In the photo: emerald and topaz crystals.

• Minerals can be found in liquids such as water. But a crystal is a solid substance that does not dissolve in water.
• A crystal has a structure made up of different materials, whereas a mineral is itself a material.
• Minerals are inorganic elements or compoundshaving a characteristic chemical composition. We have already mentioned that with the same chemical structure, minerals form completely different crystals. Therefore, the crystal structure can greatly influence the physical properties. Let’s take diamond and graphite as an example. Diamonds are considered the hardest of all gemstones, and although they have the same composition as graphite, the latter is soft and malleable in nature.

In the photo: the “Guarantees of Traditions” diamond ring from the Maxim Demidov jewelry house.

• Since minerals are homogeneous substances, it is generally accepted that crystals have magical and healing properties and are often used in various relaxation methods. Find your lucky talisman in the Maxim Demidov jewelry treasury.