I Found the Answer
Finally, I found what this is:
I cracked one of the tiny stones and the inside was black:
I guess the color has been covered by some other minerals or the color on the outside has been changed from weathering. Remember, the color of magnetite is always black.
Also, I did the streak test. The “streak test” is a method used to determine the color of a mineral in powdered form. The color of a mineral’s powder is often a very important for identifying the mineral. The streak test is done by scraping a specimen of the mineral across a piece of unglazed porcelain known as a streak plate. I don’t have a streak plate so I used a scalpel to scratch it and the dust is black. The color of the dust must be black as well.
Today, magnetite is mined as iron, that means I can claim that this is iron.
Well, another mineral is added to my collection. Just a couple more to go and this collection will be finished.