This file provides a little guide for the blue nile file bluenile.dta
This data was originally gathered by Jon Reuter.

n=2963 of which 2949 are priced for sale and 14 are past sales


The variables you will find include
rank - blue niles relative ranking of diamonds. they consider 1 to be the 
       best value for the price and so forth. Each type of cut is ranked 
       separately in the data, except round cut, which has separate rankings 
       for diamonds of that type which are ideal, very good, good, and fair. 

pct - the subjective score used to make the ranking.

type - the shape of the cut diamond.  This file contains data on three types princess, round and radiant.

Diamonds are graded by 4 basic characteristics which are the next 4 variables (often called the 4 c's)

carat - which is a unit of weight. This tells you how big the diamond is
color - recieves letter grades D-J, D being colorless ( the best).  none of the diamonds
        in this dataset is graded below H.
clarity - a perfect diamond should be a perfect crystal lattice with no interruptions.
          few are. Clarity refers to how much stuff, called inclusions and most often composed of 
          carbon flecks can be seen within the diamond, and how much magnification is required to 
          see them. Grades range from FL, or IF flawlwss diamonds, down through VVS-1 and VVs-2 
          which have microscopic inclusions to VS-1 and VS-2 which have larger inclusions to SI-1 
          and SI-2 which have inclusions you might see with the naked eye if you look closely. 
          Lower grades exist but are not in this dataset.

Cut -    refers to the geometric ratio of the angles with which the diamond was cut. Each type of 
         diamond should be cut to the proper depth to width. Cut grades from best to worst are Ideal 
         - Very Good - Good - Fair - Poor.


GIA
GCAL