mohs scale of hardness

2:21

3:05

3:14

00:57

9:38

4:37

4:45

5:20

7:56

2:19

6:46

4:14

4:08

00:42

3:32

14:47

00:58

17:43

2:24

1:33

1:13

3:50

1:37

25:49

3:23

20:37

00:29

12:23

5:32

2:46

1:19

1:44

2:50

1:41

10:39

9:05

00:23

00:30

1:14

3:43

2:07

2:30

13:25

5:30

2:39

3:26

1:06

4:32

7:18

2:10

1:12

2:47

2:48

00:32

34:18

9:33

00:57

1:56

8:55

2:48