THE ORIGIN AND FORMATION OF THE DIAMOND. I75 



One of the most notable features in both local and regional 

 metamorphism is the conversion of much of the organic material 

 of the fossils that may be present into graphite. The fossils 

 may have undergone that change just where they lie, in which 

 case the graphite takes the form of the fossils ; or, if the graphite 

 is found segregated into beds, or veins, it is supposed to have 

 been preceded by beds of coal. Occasionally anthracite has 

 been converted into graphite, but only in such cases apparently 

 by contact metamorphism at a high temperature, whereas in 

 the cas€ of the graphite that is ordinarily found replacing fossils 

 in the metamorphosed areas, we have no reason to suppose that 

 such change was ever accompanied by a very high temperature. 

 Now, there is every reason to believe that if we had a fom- 

 ])aratively easy method of making graphite the problem of manu- 

 facturing diamonds would be practically settled, as we have only 

 to bring enough pressure to bear on the material at the time 

 of formation to get diamonds instead of graphite. Speaking 

 of soft diamonds and hard graphite. Sir William Crookes declares 

 that they are in many respects alike, and that the difference 

 seems to be one of pressure at the time of formation. 



There is undoubtedly a pretty close relation between graphite, 

 which crystallizes in the hexagonal system, and diamond, which 

 crystallizes in the cubical system. There is also some relation 

 between amorphous carbon and graphite, though probably not 

 nearly so close as in the case of diamond and graphite. Un- 

 fortunately it is almost as difficult to form graphite as diamonds, 

 at least in such a way that we can easily manipulate it. More- 

 over, to obtain diamonds of any size from graphite, at the moment 

 of formation, it would have to be in a form permitting free 

 motion in its particles — in a word it would probably have to 

 be in a liquid form. The material would either have to be a 

 liquid itself or dissolved in some other liquid. I exclude gases. 

 or a mixture of such, as I fail to see how in that case, water or 

 the other inclusions I have mentioned as being found in diamonds, 

 could have been caught up in them. 



There is, as we know, a theory to the effect that the dia- 

 monds in the mines were formed by the transformation of 

 graphite. This brings us to the consideration of the relationship 

 that exists between the graphite found enclosed in diamonds 

 and the diamonds themselves. Were the diamonds formed 

 from graphite always present in the mine, and is the portion 

 of graphite we find present in some diamonds simpl\/ a residue 

 that has not been converted into diamond ? Or, have both 

 the graphite and the diamond been produced by some common 

 origin from some other kind of carbonaceous material, and in 

 the course of the transmutation of the latter into diamond, did 

 some hitch in the perfect conditions occur resulting in'j^the pro- 

 duction of graphite instead of diamond ? Or. finally, were the 

 conditions for the production of diamonds imperfect, so that 

 at first graphite was produced and then, when the conditions 

 had improved, diamond ? I cannot allow that the graphite 

 was produced in the diamond by the latter being, exposed to 



