From the point of view of science, crystal is glass with the addition of lead and potassium. It has purity and gloss, the height of these indicators depends on the amount of lead. Purity, and with it the high cost of raw materials, increase with an increase in the percentage of metal. If the content of lead oxide in it is 16-23%, the raw material is called "lead crystal." All types of crystal are glass, but not every type of glass is crystal. Products with a lead content of less than 4% is glass.
What is the difference between crystal and glass?
There are certain characteristics, the knowledge of which will help to find out whether an object is made of glass or crystal.
Sequencing:
1. Pick up an object made of crystal. Gently tap your finger and listen to a clear melody, observe the subtle vibration. To do the same with ordinary glass - a muffled sound appears that differs from the “crystal” one, the object does not produce vibration.
2. Look through crystal and glass against sunlight or bright light. Light passing through glass does not have the effect of refraction and brilliance. And what is the difference between crystal and glass? It produces a rainbow effect due to particles of lead oxide.
3. Compare items of the same size by weight. Raise crystal and glass in your hand. Paying attention to weight, it is easy to say that it is harder. Crystal lead oxide makes it harder. That is the difference between crystal and ordinary glass.
4. Pay attention to the intricate patterns of crystal products. Glass objects do not have cutouts, they are harder and more difficult to process. The presence of lead oxide in the crystal softens it, this allows you to embody decor of any complexity on products.
That's the difference between crystal and glass.
Crystal glass
Due to its properties, this material is halfway from crystal glass to expensive glass. The difference between crystal and crystal glass is the high content of lead. In the manufacture of glass, part of the lead oxide is replaced by calcium, magnesium, barium or zinc oxide, and part of the potassium oxide is replaced by sodium oxide. According to Russian standards, it must contain at least 10% oxide of lead, barium or zinc, European standards allow 1-15% of these substances. The lead content in such glass gives it a shade of bluish whiteness, the luxury of bright polished sheen and the “ringing” of crystal. It is softer than normal glass, but harder than crystal. Rubbing and intensive washing does not injure him.
Its beauty and durability are not inferior to crystal, and the low price has increased in popularity. In Russia, such products are produced at a factory in the city of Gus-Khrustalny.
What is the difference between Bohemian glass and crystal?
Bohemian glass products are highly regarded. Fine workmanship and perfect design give them a special charm. Due to the high content of lead in the raw material, which adds transparency, purity and strength to it, Bohemian glass is considered crystal. Its production is limited to the territory of Bohemia, it is one of the western regions of the Czech Republic.
Products from Bohemian glass have a number of distinctive features.
Ringing . Melodious and long, deep, slightly metal is the main sign of authenticity. It lasts at least 4 seconds, "is born from the depths and slowly subsides." Along with the sound, a slight vibration passes through the glass.
To make the product ring, it is necessary to place the item on a flat hard surface and:
- iron the edge of the product with wet fingers (the method is applicable only for products with thin walls);
- easy to hit with a crystal wand on the walls of the product;
- gently tap one product on another.
Perfect cleanliness. Components of Bohemian glass: lead and barium oxides, calcium. They increase transparency, making it clean. The criteria for evaluating purity are different for transparent and colored products.
Clear glass does not contain:
- air bubbles;
- inclusions;
- muddy areas;
- cracks on the surface;
- mechanical defects.
They check transparency by looking at brightly lit surfaces through a glass: they should not fade.
Stained glass is not completely transparent, but "clean" and has no defects. It is bright and saturated without extraneous shades, and permissible stains and overflows of the same color scheme with the main tone.
Distinctive characteristics of Bohemian glass
Surface. It is perfectly smooth, without defects such as scratches, cracks, sagging, grains. This applies to products with a carved pattern or engraving. The lines of the picture are clear, regular, without distortions, cracks and irregularities. And straight, even and thin faces are added to the right ornament.
Play of light. Due to the high refractive index, the play of light is observed on smooth and carved surfaces. Glass is checked under the action of direct rays of the sun, which, when disintegrated, play with iridescent reflections, touching the surface. Smooth products pass through the light that “plays” on the edge, connecting the legs. Carved - mirror flares reflect their faces, and the surface “flashes”.
Shape and edge of products. Technology features will not allow the creation of intricate shapes. It is always concise and correct, and a variety of design is achieved through decorative techniques. The edge is important in assessing the quality, it is always smooth, without nicks, protrusions, sag. Despite the sharpness and subtlety, the edges retain strength and remain safe.