I installed the ImageMagick binary but when I try to install RMagick
(gem) I get the foloowing error-
/usr/local/bin/ruby extconf.rb install rmagick
checking for Ruby version >= 1.8.2... yes
checking for gcc... yes
checking for Magick-config... no
Can't install RMagick 2.9.1. Can't find Magick-config in /usr/local/
bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/
X11/bin:/usr/local/git/bin

*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

What do I need to do?