J. W. Mallet—Barcenite from Huitzuco, Mexico. 309 
or 
te Ee et ee 
SiO) iol haedt ay eremal gem ag 
Sb.) 3.52.8 | a 5 
with 
BO onmniia eee 13) _ 
BO pt hee phe 4 
and an antimonate of calcium, mercury, and triad antimony 
+t 
of the formula (R°O), | . (Sb,0;);, corresponding to a normal 
Sb,05 
antimonate—M,0O . Sb,O; or M’SbOs,. 
= 120, monimolite agrees very fairly with the formula 
(RO), . Sb,0,;, or Rj’'Sb,0,; Romeite comes nearest to (RO), . 
(Sb,05), . (Sb,O;)2, or Rg'Shy’’SbyO,, (Dana makes this (R’’O)s. 
(Sb,O5)s . (Sb,05)s, or 
. NS) Bg: 
Sb,0,, correspondin 
Bindheimite the atomic ratio of PbO: Sb,O, derived from the 
* Volgerite was described as a natural antimony ocher having this composition. 
Dana Temarks (Mineralogy, p. 188), that the only published analysis, by Cumenge, 
on thaterial from Constantine, Algeria, corresponds to Sb.0;.4H.0. By my cal- 
culation Cumenge’s figures lead rather to Sb0,. 3H,0, or Sb,0, . Sb.0;. 6H,0. 
