The stones you posted are not well cut and they certainly don't match well.
To learn more about what makes a well-cut stone...read this
Diamond Proportions
The physics of light-behavior within a diamond are reliably consistent, which means proportions measurements can be useful.www.pricescope.com
The easiest way to pick two good stones is to go with Super Ideals because we already know they are well-cut. Just need
to pick two that are relatively close in diameter.
Here is an example of two nice ones $4256 + settings. (there are lots of other choices)
Diamond | 0.515 ct F VS2 A CUT ABOVE® Hearts and Arrows Super Ideal Round Cut Loose Diamond AGS Certified | 4410613
This Whiteflash A CUT ABOVE® super ideal cut hearts and arrows 0.515 carat F color VS2 clarity loose diamond is graded by the American Gem Society (AGS) Laboratories. | 4410613www.whiteflash.comDiamond | 0.511 ct F VS2 A CUT ABOVE® Hearts and Arrows Super Ideal Round Cut Loose Diamond AGS Certified | 4410615
This Whiteflash A CUT ABOVE® super ideal cut hearts and arrows 0.511 carat F color VS2 clarity loose diamond is graded by the American Gem Society (AGS) Laboratories. | 4410615www.whiteflash.com
Settings
Shop Online for Diamond Stud Earrings | Whiteflash
Purchase the highest quality designer Diamond Stud Earrings at Whiteflash, featuring internationally recognized Diamonds and a wide selection of Designers.www.whiteflash.com