免费看国产黄色片,可免费观看情趣视频网站,国产AV影片麻豆精品传媒,久久久无码精品一区二区三区蜜桃

Brown corundum is widely used in the industrial production field, so there are more and more manufacturers now, which leads to a significant difference in the quality of products on the market, making it difficult for users to distinguish their quality. In fact, it is not difficult to distinguish the quality of brown corundum products, as long as you master the following aspects.

Usually, we can judge the quality of brown corundum by its shape, color, and size.

1. Shape: usually the small particle shape of a ball. Smaller colors are lighter, while larger colors are darker.

2. Size: Determine the quality from the original minerals. A good original mineral surface looks very bright and shiny, and the size is very small.

3. Color: The color is a typical purple, which looks transparent and glossy. Usually, they are very transparent and are good brown corundum. Just like those black, opaque, rose or light colored products on the market, please purchase with caution.

As is well known, the quality of brown corundum determines its performance and effectiveness, so it is important to learn a few techniques and methods for judging quality when purchasing. In addition, when purchasing products, one should not only aim for cheap prices, but also make a comprehensive comparison of what you pay for. Additionally, it is important to purchase from reputable manufacturers.