Hello, how to judge the grade of hematite lump ore with naked eyes and hands without chemical experiments? Thank you, it's urgent

This is not easy to handle, and it is still a lump of ore ~ ~ The following methods are for reference:

1, it should not be possible to look at it directly with the naked eye, because there are many variation forms of hematite, and the appearance of each form is also very different, so it is basically unreliable to judge by appearance.

2. Use stripes. The stripes of hematite are cherry red, regardless of crystal size and shape. Take a piece of ceramic, draw a line with ore on the unglazed side, and draw all the edges, so that the judgment level is the lowest. PS: If your painting is golden yellow, congratulations, you have dug a gold mine, hehe, just kidding.

3. Utilization density: the density of hematite is above 5.0, and the density of gangue is generally above two points, such as 2.6, 2.7 and 3.0. You can also know the range of ore grade by measuring cup and balance.

4. If you have basic experimental instruments, it is easy to grind the ore into powder. The redder the powder, the higher the hematite content, which means hematite content, not iron content.

5. It is better to have a strong magnetic block. Hematite is still weakly magnetic. Pour the ground hematite powder into water, and hold it with a strong magnetic block with N thousand field strength. Although hematite can't be completely sucked out, the final result is still of reference value.

Answer supplement:

Hematite around 60 or 65 is hard to say, but it can be ground into fine powder, poured into a very shallow plate (palm if skilled), added with some water, shaken and dumped. Add water until the water becomes clear (basically three or four times). If the remaining iron powder is black and greasy, and even feels a little blue, it means that the grade is very good, above 65%; If the color is black, there is no obvious impurity particles such as timeliness, and the grade should be around 60%. Experience is very important. If you are skilled, the judgment result is quite reliable.