Bob Engelhardt wrote:

http://home.comcast.net/~bobengelhardt/drill1.jpg (37kB)
http://home.comcast.net/~bobengelhardt/drill2.jpg (43kB)

I found this bit at the dump. It has a tapered shank & is marked "star
- hammer - twist". It has a chisel point, not a cutting lip, so it
clearly does impact cutting & hence (?) is for masonry. But it is not
carbide tipped! It has some rust, so it can't be solid carbide, can it?

So, I guess the question is: is there some steel alloy that is used for
masonry impact drilling?

Answer: Certainly, people were drilling masonry and rock long before
high tech materials like carbide were available.