COLORADO FERBERITE AND THE WOLFRAMITE SERIES. 65 



DESCRIPTION OF MEASURED CRYSTALS. 



Only such crystals as arc illustrated by drawings will be hero 

 m< MI tinned. The general types of habit have already been shown 

 under the section entitled "Habit," where drawings of a few of the 

 measured crystals were also introduced. In general the following 

 figures show the crystals in their ideal development. As most of 

 thorn were bounded on one side by the cleavage face (OlO) the exact 

 dimension of the crystals in this direction could only be estimated, 

 but by observing similar crystals that were intact it is believed that 

 the proportions shown in the figures closely approximate the true 

 relative dimensions. The crystals illustrated will bo grouped under 

 the five habits. 



Crystal 29 (fig. 19) is simple in its combination but shows the 

 rare form ^{214} fairly well developed. It is, moreover, except 

 c{001}, the only terminal form on this crystal. Crystal No. 32 (fig. 

 20) shows a common combination for a number of minute stout 

 crystals in which the wedge shape is not so characteristic as in crystal 

 No. 33 (fig. 21). Here also the upper and lower faces of /{Oil} arc 

 unequally developed. With the large development of Z{210} the 

 pyramid faces generally become smaller. 



Crystal 5 (fig. 22) is remarkable in possessing such a small ortho- 

 pinacoid, a{100}, the large faces of n{S10} seeming to replace 

 the usually large faces of a. Crystals 6 (fig. 23) and 9 (fig. 24) are 

 both shown in their actual condition, with one side bounded by 

 the cleavage face (OlO). Both of them show a line face of the rare 

 negative dome /-{T.0.11} and figure 24 also shows the large positive 

 dome {102}. The rare prism d{310} is shown as a line face, and 

 a face of 7" {6 10}, though not shown, is also present. Crystal 13 

 (fig. 25) shows a number of new and rare forms, all as narrow faces, 

 generally mere line faces, except one form which is present as a 

 minute equidimensional face. The new forms 7/{904}, .A {337}, 

 {123}, and the rare forms n{8!0} and ^{104} are the ones referred 

 to. The clinodome, /{Oil}, is much narrower and longer than 

 is usual for the faces of this form. Crystal 16 (fig. 26) gives a 

 combination seen on numerous crystals not measured. The new 

 form //{904} is generally present on such crystals. Crystal 17 

 (fig. 27) shows y"{610}, n{810}, and o{Tll} besides the more common 

 forms. Crystal 18 (fig. 28) shows the striations observed on J{112}, 

 these striae being parallel to the intersection edges (112) : (001) 

 and (112) : (210), respectively. The crystal is also more elongated 

 in a vertical direction than is usual. Crystal 19 (fig. 29) shows 

 a number of new pyramids, namely, D{313}, {123}, "{5.9.14}, 

 and the rare pyramid >{214}. The zonal relationships of J(112), 

 #(5.9.14), (123), /(Oil), and m'fflO) could be weU seen on this 

 crystal. Crystal 20 (fig. 30) also shows the new form "{5.9.14}, as 

 weU as ^{337} and 77{904}. 

 35659 Bull. 58314 5 



