In the field of industrial applications, granite is highly favored for its hardness, durability, beauty and other characteristics. However, there are some cases in the market where marble substitutes are passed off as granite. Only by mastering the identification methods can one select high-quality granite. The following are the specific identification methods:
1. Observe the appearance features
Texture and pattern: The texture of granite is mostly uniform and fine spots, composed of mineral particles such as quartz, feldspar, and mica, presenting starry mica highlights and glittering quartz crystals, with an overall uniform distribution. The texture of marble is usually irregular, mostly in the form of flakes, lines or strips, resembling the patterns of a landscape painting. If you see a texture with obvious lines or large patterns, it is very likely not granite. In addition, the finer the mineral particles of high-quality granite are, the better, indicating a tight and solid structure.
Color: The color of granite mainly depends on its mineral composition. The higher the content of quartz and feldspar, the lighter the color, such as the common grayish-white series. When the content of other minerals is high, grayish-white or gray series granites are formed. Those with a high potassium feldspar content may appear red. The color of marble is related to the minerals it contains. It appears green or blue when it contains copper, and light red when it contains cobalt, etc. The colors are more rich and diverse. If the color is too bright and unnatural, it may be a deceptive substitute for dyeing.
Ii. Test physical properties
Hardness: Granite is a hard stone with a Mohs hardness of 6 to 7. The surface can be gently scratched with a steel nail or a key. High-quality granite will not leave any marks, while marble has a Mohs hardness of 3 to 5 and is more likely to be scratched. If it is very easy to have scratches, it is very likely not granite.
Water absorption: Drop a drop of water on the back of the stone and observe the absorption rate. Granite has a dense structure and low water absorption. Water is not easy to penetrate and diffuses slowly on its surface. Marble has a relatively high water absorption capacity, and water will seep in or spread quickly. If the water droplets disappear or spread quickly, they may not be granite.
Tapping sound: Gently tap the stone with a small hammer or similar tool. High-quality granite has a dense texture and makes a clear and pleasant sound when struck. If there are cracks inside or the texture is loose, the sound will be hoarse. The sound of marble being struck is relatively less crisp.
Iii. Check the processing quality
Grinding and polishing quality: Hold the stone against the sunlight or a fluorescent lamp and observe the reflective surface. After the surface of high-quality granite is ground and polished, although its microstructure is rough and uneven when magnified by a high-power microscope, it should be as bright as a mirror to the naked eye, with fine and irregular pits and streaks. If there are obvious and regular streaks, it indicates poor processing quality and may be a counterfeit or substandard product.
Whether to wax: Some unscrupulous merchants will wax the surface of the stone to cover up processing defects. Touch the surface of the stone with your hand. If it feels greasy, it may have been waxed. You can also use a lit match to bake the surface of the stone. The oil surface of the waxed stone will be more obvious.
Four. Pay attention to other details
Check the certificate and source: Ask the merchant for the quality inspection certificate of the stone and check if there are any test data such as radioactive indicators. Understanding the source of the stone, the quality of granite produced by regular large-scale mines is relatively more stable.
Price judgment: If the price is much lower than the normal market level, be vigilant that it is a counterfeit or shoddy product. After all, the cost of mining and processing high-quality granite is there, and a price that is too low is not very reasonable.
Post time: Jun-17-2025