Gemstone photography

[Kingsolomon]

I've just noticed that the cannon is 18 mp and the Nikon has 24 mp , since most of my photos will be viewed on the web , what would be a better choice? And if I should get a Nikon , i guess a basic one , they all seem priced similar in the lower range , most about $600-1000 , any of them a better choice for what I'm doing?nikond5500.? Has hd video too .