Sharpened is a verb not a noun
sharped, sharpened
190mm
F sharp
The point of a sharpened pencil.
axes, sharpened sticks, arrows
axes, sharpened sticks, arrows
Cavemen made stone weapons such as crude spears which were probably a sharpened stone tied on a long stick.
so they first found a rock then they sharpened so they can use it for hunting
They sharpened stones by rubbing them on other stones.
People in the Stone Age used sharpened sticks as hunting tools and weapons because they were effective for stabbing and throwing at prey. They were readily available and easy to craft from natural materials, making them a practical choice for survival in that era.
That means a sharpened knife. The knife has been applied to a whet stone and is nice and sharp.
sharpened
The first humans crafted tools and weapons from animal bones and rock sharpened against stone to hunt.
The materials are actually pretty much the same even if you are using an electric grinder. The knife is sharpened by using consistent strokes across a stone such as an oil stone, water stone, or diamond stone, etc.
Your canine teeth can be sharpened by going to your dentist, where he/she will probably add a contour in place, but if you mean 'sharpened' like a pencil sharpened, then talk to your dentist about that.
Not only does the oil cool the metal being sharpened but it prevents the stone from loading up with metal.