I was thinking that La Capitaine is the best mac OS X icon theme for Linux. But recently, I realize that there is another great icon theme that will make your Linux looks like Mac OS X. It is macOS Icon Theme. All the icons were rendered in high resolution so it is very clear on your desktop. For me, this macOS icon theme is too perfect to mimic the original MacOS X icons.
Those are some screenshots of my Fedora 27 with this macOS icon theme. If yo are interested with this icon pack, you can download using the link below.