1, different materials
Crystal is a crystal of silicon dioxide, while glass is just a molten mixture containing silicon dioxide.
2, the effect is different
Glass has only decorative function, while crystal has piezoelectric effect in addition to decorative function and has special health care function.
3. Different prices
The unit price of crystal is several times or even dozens times higher than that of glass.
4. Different physical properties
(1) Crystal has a high hardness (Mohs 7), while glass has a low hardness (Mohs 5.5), so the crystal can mark the glass, otherwise it can't.
(2) Crystal is a kind of crystal with good thermal conductivity, and it will feel cold when touched with the tip of the tongue. The glass looks warm.
(3) Using a polarizer, crystal can transmit light, but glass can't.
5, the processing technology is different
Glass can be hot-cast, which saves material and labor and has low cost. Crystal is a crystal, which is irreversible after heating and melting, so it can't be molded by hot casting, but only by cold working methods such as cutting and grinding. Waste of materials and manpower, high cost.
How to distinguish glass from crystal (according to their physical properties)
1, touch the gem with your palm or lips, and the crystal stone is cold; The glassy imitation crystal has a sense of temperature.
2. Check with a polarizer: the rock crystal has four bright and four dark changes when rotated 360 degrees under the polarizer, but the glassy imitation crystal has not changed.
3. Check with dichroism: natural amethyst has dichroism, while glassy imitation crystal has no dichroism.
4. Use feldspar with hardness of 6 as the test stone, and draw gems on the feldspar. What can draw the same score is crystal, and what slips is glassy imitation crystal. If there is no feldspar, it can also be painted directly on the glass. What can draw a score is crystal, and what has no score is glassy imitation crystal.
5. Test with a thermal conductivity meter: set the thermal conductivity meter to 4 squares of green to test the gem, and the crystal can rise to 2 squares of yellow, while the glass imitation crystal product does not rise, and rises to 1 square yellow when the area is large.
Extended data
Glass and crystal wine glasses:
Thick glass goblets will reinforce the edges of the goblets to ensure the firmness, but this will not improve the tasting experience. Because the main component of glass is silicon dioxide, the molecules of this substance are not easy to react with other substances, so it is an inert substance.
Moreover, glass is airtight, and it is not easy to leave aromatic components in the detergent or be corroded by the detergent when cleaning with a cup washer, so the price of glass glasses is usually low.
Crystal wine glasses are not made of crystal, but are made by adding 2%-30% minerals to glass. This mineral is usually lead, and its function is to strengthen the glass material, so that the made wine glass can meet both light and durable conditions.
Crystal wine glasses, more precisely, those containing lead or minerals, because of their thin and solid walls, will make a crisp sound when touching the glass. Lead-containing crystal wine glasses have excellent performance in refracting light, and are more transparent and clear when observing wine liquid.
There is a crystal wine glass on the market that does not use lead, but uses a certain proportion of magnesium and zinc instead. This kind of wine glass not only has the advantages of lead-containing crystal cups, but also can be cleaned by a cup washer.
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