354 PROCEEDINGS OF THE CALIFORNIA 



Some remarks followed upon sun and moon halos, during which 

 Dr. Gibbons combated the popular notion that halos about the moon 

 were infallible signs of rain. His observations proved that, in some 

 seasons, these signs invariably failed in California, and at the East ; 

 he thought no rule could be established on the subject. 



Mr. Goodyear presented the following paper in behalf of Pro- 

 fessor Silliman: 



Notice of New Localities of Diamonds in California. 



BY B. SILLIMAN. 



Every well-authenticated instance of the existence of the diamond in the 

 United States is of interest, since it serves to enlarge our knowledge of the 

 geographical and geological distribution of this much esteemed gem. 



I have the pleasure of exhibiting to the Academy four diamonds, obtained 

 from separate localities in this State. Three of them are crystals, having the 

 form of an icositetrahedrou ; the other has been cut, and is set as a ring stone. 



The First Specimen — Is from Forest Hill, in El Dorado County. Its weight 

 is 0.3G9 gramme, or 5.673 grains — equal to rather less than 1}£ carats. Its 

 color is good, but it has a small cavity and discoloration on one of the solid 

 angles, and it is less symmetrical than the second specimen. This crystal was 

 found at a great depth from the surface in a tunnel run into the auriferous 

 gravel at Forest Hill. I procured this stone from Mr. Tucker, the well-known 

 jeweler. 



The Second Specimen — Is from French Corral, in Nevada County. It weighs 

 0.3375 grammes, or 5.114 grains — equal to about l} 3 carats. Its form is sym- 

 metrical, color slightly yellowish. Its lustre has been dimmed slightly by hav- 

 ing been subjected to a red heat as a test of its authenticity. The auto da fe 

 is hardly the test a chemist would select for pure carbon ! It is remarkably 

 destitute of flaws. This crystal was washed out from the cement in the deep 

 gravel washings for gold at French Corral, and was found in the sluice boxes. 

 It belongs to Mr. Egbert Judson, of San Francisco, from whom I derive this 

 information. 



The Third Specimen — Is smaller and less perfect than either of the preceding. 

 It was found at Fiddletown, in Amador County. It weighs 0.2345 gramme, or 

 3.619 grains— a little less than one carat. This crystal is distorted, and has 

 several reentering angles and cavities. Mr. M. W. Belshaw, to whom it be- 

 longs, informs me that since 1855, five diamonds have, to his knowledge, been 

 found at Fiddletown, where he then resided ; none of them weighing much over 

 one carat. All these specimens were found in a gray cemented gravel under- 

 lying a stratum of " lava " or compact volcanic ashes, and were found in search- 

 ing for gold. 



