dataset:  marbles_classify.csv

Source: A.B. Yasuv, M. Bruno, D. Attanasio (2011). "An Updeated,
Multi-Method Database of Ephesos Marbles, Including White, Greco Scritto
and Bigio Varieies," Archaeometry, Vol. 53, #2, pp.215-240.

Description: Classification of 244 marbles with respect to various
characteristics.
Group: 1=White Marbles: Ephesos-1 Group (n=88)
       2=White Marbles: Ephesos-2 Group (n=38)
       3=White Marbles, Aya Klikiri Group (n=10)
       4=White Marbles, Farm Quarry Group (n=14)
       5=Greco Scritto Marbles: Hasancavuslar Quarry 1 (n=19)
       6=Bigio Antico Marbles: Belevi and Mt. Panayir Quarries (n=75)
Other variables:
id    # numeric
sample_id   # alphanumeric
quarry
d18O        # oxygen isotopic ratio
d13C        # carbon isotopic ratio
epr_inten   # EPR spectral intensity
epr_linwid  # EPR linewidth
colour      
mgs         # maximum grain size