The Origin and Properties of Crystal

The discovery and formation of crystals

The stones shone brilliantly in the light of the blazing fire. He knocked it down and carefully polished it into stone axes, scrapers, arrowheads and even neck ornaments. Four hundred thousand years later, researchers discovered this ancestor's remains in Zhoukoudian, alongside utensils made from this crystal stone, later named crystal.

Take the narrow sense of water - white crystal formation as an example, explore the mystery of crystal formation.

The stones shone brilliantly in the light of the blazing fire. He knocked it down and carefully polished it into stone axes, scrapers, arrowheads and even neck ornaments. Four hundred thousand years later, this ancestor was found in Zhoukoudian, still with the utensils made of this crystal stone. This stone was later called crystal
Take the narrow sense of water - white crystal formation as an example, explore the mystery of crystal formation.

Tens of millions of years ago, due to volcanic eruptions, the magma inside the Earth moved from the center to the surface. Most of the magma flowed out of the ground and became black volcanic rock. And the other part of the magma under the action of geological formation of various gems.
Underground, silica magma spread out, with most of it cooling and solidifying under soil and rock pressure, turning into the quartz we see today. Some lava that didn't crystallize cooled quickly, forming obsidian. After cooling and solidification, groundwater dissolved parts of the magma containing silica gel and calcium carbonate. In caves, this mixture dripped slowly, forming stalagmites, stalactites, or turning into opal over time. Silica magma colloids precipitated in soil cavities, solidifying into maolu. Elsewhere, exposed to air in soil and rock holes, it condensed on walls, forming today's water products and creating "crystal holes."

These "crystal caves" look like ordinary stones from the outside, but when cut open, the walls of the caves inside are lined with finger-sized, hexagonal crystals (some of which can be several feet long, of course). The Geological Museum of China has a crystal king weighing 3500 kg.) The narrow crystal in the picture is actually a kind of quartz stone in terms of composition. When silica is perfect, it is crystal in a narrow sense. After silica gel dehydration, it is Ma. After silica colloid containing water solidifies, it forms opal.

Compared with general quartz, the conditions of crystal formation are more difficult to carve, first of all, there must be abundant space for growth; Secondly, there should be a hydrothermal solution that provides material, that is, a hydrothermal solution rich in silicon dioxide. Thirdly, there should be a high temperature and pressure. Fourth, there is time to grow. These four conditions are required to generate crystals.
In nature, the developing joints, cracks and faults are good Spaces for the growth of water products. Water crystal primarily form in veins within granite, normal rocks, and their adjacent quartzite, quartz feldspar sandstone, phyllite, and schist rocks. Structural fractures control their formation, which occurs through a filling process. When rocks undergo strong development or metamorphism, they can supply ample hydrothermal fluid.The hydrothermal fluid itself has a good temperature and pressure to provide a good condition for the formation of water products. The final required growth time is more readily available. Hundreds of millions of years of Earth does not lack these conditions, which is why crystal mines are now spread all over the world.

Factors influencing crystal formation

Crystal has a variety of colors, such as purple water products, white crystal, tea crystal, tobacco water products, black crystal, and colorless water products.
Not every crystal is perfect. During growth, surrounding substances like iron and aluminum can influence the crystal's color and luster. Aluminum tints crystals smoky gray, forming "smoky water products," and iron turns them dark red, creating "rose water." High-intensity radiation also influences their growth and color. Pure, transparent crystals need an environment free from rays and trace elements. Temperature variations in hydrothermal solutions and mixed mineral distribution often give a single crystal multiple colors.Such as colorful body water products. A piece of crystal mixed with purple and white, hair crystal of various colors, etc. Under the irradiation of the sun, these water products are usually golden and glittering, presenting a spectacular scene of "light emitting the earth, treasure gas emitting rosy clouds".
Because the earth's crust is in constant motion, not all the formation conditions are the same, shaking, temperature change, the lack of hydrothermal will affect the formation of water products, at least will affect the quality and size of water products. The gorgeous and colorful crystal in front of us is really the essence of heaven and earth. In fact, all the mineral objects that can become gems are also the same. This is one of the reasons why people love gems since ancient times

Properties of crystal

The basic properties of crystal
Water (Rock crystal) mineral name is quartz (Quart2), mineralogy belongs to the quartz family. It is a single crystal of quartz, which is the most common rock-forming mineral in the earth's crust. It is also a large number and range of gemstone materials.

Chemical composition

The main mineral in the chemical composition of the crystal is silica (Si02), which is colorless and transparent crystal when pure. Sometimes it contains some trace elements, such as aluminum, iron, etc., resulting in different colors and properties of the crystal.

Crystalline nature

In crystallography, crystals belong to the intermediate crystal group, the tripartite or hexagonal crystal system. The common crystal form is columnar, sometimes plate. The main monotypes are hexagonal columns, rhombohedral bodies, tripartitic bicones and tripartitic bodies, and the crystal surface will appear transverse texture.

Optical properties of Crystal

• 1.Color: pure crystal is colorless, when the crystal contains other trace elements, will appear purple, yellow, brown, black, pink, rarely produce green.
• 2.Gloss: crystal generally presents glass luster, when the table is damaged, there will be grease luster like fracture. Sometimes the original stone crystals take on a waxy luster due to dissolution.
• 3.Transparency: crystal is transparent when it is pure. The transparency of colorless crystal can be very high, which is a good optical instrument. However, with the increase of inclusion content or the deepening of color, the transparency will decrease until it becomes opaque.
• 4.Optical property: the crystal is one axis of normal optical property, and its axis interference pattern is a special hollow black cross shape, also known as "bull's eye" interference pattern.
• 5.Polarizer phenomenon: in the polarizer into four bright and four dark phenomenon, for the anisotropy.
• 6.Refractive index crystal has a low refractive index of 1.544-1.553 and a double refractive index of 0.009. Therefore, the fire color of crystal is low and the luster is weak.
• 7.Polychromatic: only for colored crystal, its polychromatic strength and its body color depth related. Such as amethysts have clear dichroism, topaz and tea crystal have weak dichroism.
• 8.UV fluorescence: crystal without UV fluorescence phenomenon.
• 9.Spectral absorption: the absorption spectrum of crystal without characteristic
• 10.Special optical effects: when containing characteristic inclusions, the crystal will appear cat's eye effect and star effect.

Other properties of Crystal

Single crystal crystal is piezoelectric, not only when the surface of the crystal is under a certain pressure, the front and back ends of the crystal will generate the corresponding amount of charge, and the amount of charge is proportional to the pressure. Therefore, crystal can be widely used in scientific and technological fields, such as quartz resonators for permanent frequency regulation. In addition, crystal is rich in magnetic field, and wearing crystal products for a long time helps the blood circulation of the human body.
Crystals can sometimes contain rich inclusions inside. Amplification is common for two-phase inclusions, gas, liquid, solid and other single or three-phase inclusions, the development of obvious ribbons and solid rutile needle, tourmaline column and crystal negative inclusions. And the inclusion of crystal is of great significance in its classification.