NOTES ON VARIOUS MINERALS IN THE MUSEUM 
GCOBEEC TION 
BY OLIVER CUMMINGS FARRINGTON AND EDWIN WARD 
Herre ON a dR: 
ANGLESITE 
TINTIC DISTRICT, UTAH 
PLATES XLV AND XLVI 
An especially fine series of crystallized anglesite, received from 
Maynard Bixby, all from the Tintic District, Utah, and chiefly from 
Eureka, afforded material for a study of the crystal habits of the 
mineral. The specimens were the choicest of many that had been 
collected by Mr. Bixby, and are probably, therefore, the best represen- 
tation of the anglesite of the locality that has yet been obtained. 
The crystals occur almost wholly in cavities in galena, the cavities 
as a rule having a diameter of from 1 to 4inches. The galena shows 
a coarse, granular structure asarule. The crystals of anglesite occur- 
Oring in these cavities are for the most part colorless, but some are 
white and several show a tinge of yellow, in some cases a deep canary 
yellow; others exhibit smoky or gray shades. Asa rule the crystals 
are nearly transparent, some completely so, but others show cloudings 
_ which may be so abundant as to make the crystals practically opaque. 
As is usual with anglesite, the lustre is highly adamantine in some 
specimens, but in others more nearly vitreous. The crystals vary in 
size from minute, lining druses, to one having a length of 4.5 centi- 
meters (134 inches). For the most part a length of about 8 milli- 
meters may be considered descriptive of the size. The crystal planes 
as a rule are well developed and afford fairly good measurements with 
the reflecting goniometer. Not infrequently, however, the surfaces are 
more or less uneven so that only broken reflections are obtained. 
The planes of the different forms are as a rule uniform in lustre and 
character of surface, with the exception of the macropinacoid, a (100), 
which is nearly always characterized by being striated in the direction 
of the vertical axis. It can usually be recognized by the naked eye 
131 
