224 FreLp CoLumMBian MusEuM—GEOLOGY, VOL. I. 
4 H,O, 6 (Mn, Ca) O, 6 Si O,, or H, (Mn, Ca), 51, O,, + 3H, O: Com= 
paring the percentages called for by the formula, with the writer’s 
analysis calculated to 100% (reckoning Fe Oas Mn O), the results are 
as follows: 
Analysis Calculated 


Theory. to 100. 
Bl Oc. Tse t ok ORAM E ee eee 42.91 44.76 
$4 GN yD) ceca eal ace et epee tee ee 40.51 38 .86 
2 OCS OY ee een ar Porte ae nee 8.00 8.21 
Ar ELS Oe a eect cine eras eee eee ee 8.58 8.17 
100. 100. 
Here the greatest discrepancy to be noted is in the percentage 
of Si O,, which is noticeably higher in the analysis than the theory 
callsfor. MnOjs also a little lower. Yet it is believed that this 
formula better agrees in general with analyses of the mineral and bet- 
ter expresses its constitution than any hitherto proposed. Flink’s 
formula, 2 (Mn, Ca) Si O, + H, O, reckons all the water as water of 
crystallization, which is clearly incorrect. Moreover, the percent- 
age of Mn O called for by his formula, 41.4%, is larger than has 
ever been obtained. Barwald’s formula, R (ROH), Si; O;, + aq., 
gives percentages nearly like that proposed by the writer, but the 
compound represented by such a formula would less resemble other 
zeolites in manner of constitution than does that of the writer’s 
formula. Moreover, one would expect a darker color if the molecule 
Mn OH were present in the mineral. 
CALEDONITE. 
STEVENSON-BENNETT MINE, ORGAN MTS., NEAR LAS CRUCES, NEW MEXICO. 
MUSEUM No. M 5486. 
A single specimen of this mineral was picked up by the writer 
on the dump of the Stevenson-Bennett mine in the spring of 1896. 
It is the only specimen ever found there, so far as I am aware. It 
is also the second or possibly the third occurrence of the mineral 
reported in America. It is known to occur* at the Cerro Gordo 
mines in California, and has been reported from Mine la Motte, 
Missouri, but the report needs confirmation. In the specimen 
secured by the writer the mineral is in the form of several distinct 
*Dana’s Mineralogy, p. 925. 
