Of 0 XFO %T)^SHI%E- 97 
of there are fome in the Qiiarrys near Sbotover^ fo clear and hard, 
that they come not much behind the BriJicl-§iones^ and are in fi- 
gure (though had from the fame Quarry) as various as Diamants ; 
fome of them being comprifed mfeven^ others in nwcj others in 
ehvtn^ and fome in thirteen planes, as may eafily be computed 
from their trigonal^ tetragonal ^fentagonal^d.nd. he-xagonal pyramids^ 
reprefented in Tab. '2,. Fig. lo. to which, adding the planes of their 
columns^ and the planes of their bafes^ whereby they are fix'd to 
their fubjefts, thofe numbers of Hedr^e mufl: needs be concluded. 
52. As to the origimnd texture of Spars^ 1 take them to be 
much of the fame with Chryftals (though we feidom find them 
of their bexagona I figure, or their columns ever interceding two 
pyrairdds') and that they differ in lufter and hardnefs according to 
themore clofe or ioofe texture of the/i?;?^^ whereon they fit, and 
out of v/hich they have fweat, as through a flrainer or colander. 
Though it mud not be denyed, but what is afiTerted by the inge- 
nious and obferving ^S/ewo concerning Chryftals, may have place 
alfo in the increafe and growth of thefe, which he fays (what- 
ever may be the manner of their firfi: delineation) is by external 
appofirion of new Chryflalline matter to the external//^/2e^ of the 
already delineated Chryftal ^ which he alfo obferves, not to be 
joined to all its planes, but for the moft part to the planes of the 
top only ; nor to thefe all at a time, nor in the fame quantity* 
Whence it is, that the extream or top pldnes of Spars as well as 
Chryftals, are feidom or never equal, and not always triangular, 
but riling with unequal ftdes and angles from the planes of their 
columns, as in that feparate piece of Spar or Chryftal near ¥ig. 10. 
which I take to be arguments fufficiently concluding the fimilitude 
of their growth and texture of parts, notwithftanding the planes 
of the columns of ^'/^^jnare notftreakect, nor fo plainly fhew the 
places of appofition, as they do on Chryfial ; which ftreaks, for 
the Readers more ready apprehenfion, are therefore cut on the fe- 
parate column near Fig. 10. though otherwife indifferently to be 
underftood either for S par or Chryftall. 
53. Some of thefe Spars fall fo little fliort, either of Chryftals 
or BriftolDiamants, either m lufter or hardnefs, that we may very 
well admit what is faid of them by Aldrovandu6^, that they are 
gemm-e inchoated, isfnon pcrfeS^dC, And that Boetiu^^ in all likely- 
^ FrodvQra, de ChryflaUo-pro^of.tio?iih- l-> 7, 3. » Mufam?i Metall. db. 75. ^ DeLabid.c^ 
Gem. cijy. 30-j.. 
N hood 
I 
