Mohs Hardness Scale (again)

We're identifying minerals in science, and one of the properties we're using is hardness. I have much to complain about Mohs Hardness Scale.
The easiest test is using fingernails. If you can scratch it, it's a 1-2. However, some people have really, really sharp fingernails! In fact, someone's very sharp fingernail cut me today, and I started bleeding a lot more than I had expected...
Next, there is the copper penny. What if the school you went to was so poor that they couldn't afford copper pennies for everyone? Or, what if you didn't go to school in the US? How could you get your hands on a COPPER PENNY? A lot of smart countries don't even HAVE pennies. Like China. They also don't have more than one time zone, which is even smarter.
The next test would be the steel file. However, we used a nail in our experiments. The point of a nail is very sharp. But it wasn't a file. It was a nail. Nails aren't files, and files aren't nails.
Now comes the glass. MHS mentions "glass" and "hard glass". Again, different countries probably might not know how the US judges "standard glass". In China, the paper bags are incredibly thin, and so is the paper. I'm glad we don't use bags and paper to measure hardness...
And, finally, quartz , topaz, corundum, and diamond. They probably couldn't find any extremely hard "common items", so they had to just use minerals. I don't know about you, but I certainly don't have any quartz, topaz, corundum, or diamond lying around at home.
This is probably why we're doing the mineral lab at school, but it's still incredibly difficult to measure the hardness, and hard to tell if it has cleavage/fracture for some of them. Even the color is inconsistent, and most of the streaks are white. Luster hasn't helped me at all.
If my lab partner hadn't licked the halite, I don't know what I'd do for mineral #5.