RECORDS OF MEETINGS 215 



above noted. This has furnished a number of specimens remarkable for 

 their large flames of red, strongly resembling lumachella marble. A 

 number of these are lusterless, and many of them are more or less 

 cracked, partly due to the fact that they have a large water content, and 

 partly because a number of them have been found very near the surface. 

 In some respects, the formation resembles the deposit discovered in 

 White Cliffs, New South Wales, where some of the opals are pseudo- 

 morphs, being opals after wood or other objects. There was a newer find 

 in 1911, a limb of a tree measuring fifty centimeters, or nearly two feet, 

 in length and eight centimeters across; this was entirely changed to 

 opal; the outer parts were very brilliant, whereas the center was of the 

 dull, common opal variety. Some of the opals are equal to the finest 

 Mexican material, the colorless and a number of new varieties. 



In nearly every instance, these masses are found in decomposed vol- 

 canic rock, or in ash that has hardened. Apparently there must have 

 been a later flow of opaline waters to change them to this form. The 

 deposit is west of the Santa Rosa Mountains and near the Trout Forest 

 Range and the Pine Forest Range. Some of the stones cut several years 

 ago still hold their color, but it is possible that a number of them may 

 not be of the more durable type. This is the most interesting occurrence 

 of opal that has yet been noted in the United States. The deposit found 

 in 1909 was traced to a depth of 16 feet, whereas the opalized tree and 

 later deposits above mentioned were found at a depth of only two feet. 



There have at various times come to me various opal from Lovelock, 

 in the southern part of Humboldt Co., Nevada, and wood opal from 

 the northeastern part of Humboldt Co. ; also opal in concretionary masses 

 from Austin in the southeastern corner of Lander County, as well as from 

 Caldwell, Idaho, Rockville and Score Creek, Owhyhee County, Idaho. 

 There was opal also from Clover Creek, Lincoln County, in the Snake 

 River region in the southwestern part of Idaho and from Baker and 

 Durkee in Oregon, Walla Walla, Douglas County, and Whelan near 

 Mexico, Idaho, as well as near the Salmon River. This furnished the 

 finest precious opal that has been found on the continent, the opal oc- 

 curring as nodules in a very hard trachitic rock resembling the rock in 

 which the precious opal is found in Hungary. A single stone was worth 

 one thousand dollars. An impure variety has been found in Dunsmuir, 

 Siskiyou Co., northern California. Opal is also found in the desert 

 near Reno, and it is possible that it may be found in many places near 

 there, both in excellent gem varieties as well as the finer qualities. Re- 

 marks were made by Professor Martin. 



The Section then adjourned. Charles P. Berkey, 



Secretary. 



