Arizona republican., 1917-06-17
6be MINES of ARIZONA

The Republican will conduct d series of questions and answers to which the public is invited to submit all questions regarding mining metal luIsy, geology, peuoglapHy, inning law, mining practice, etc. Qu2 2llIatlVe deteImiations of rocks and ores will be made free, and all questions Wlil be answered through th4s column. Questions will not be published in full, bal only enough to make them inteiiigible to oUi ie,,lerS. Address all samples and communications to Charles r. Willis, director, Arizona State Bureau of Mines, Tucson.
 The infoI nation service Cf the state bureau of mines is growing more eX- tensive and intricate, for not alone does the bureau answer all kinds of questions relating to mining and it's allied industries, but other kinds of inuuiries, as the following letters, re- ceived recently
 "On the second day of February this year. our only child, John Carlos McManus, age p. left our home in Long Beach, Calf. He left us with out a word, just dropping out of our lives. put We heard indirectly that he was working in mine in Arizona. N e would greatly appreciate it if you could assist us in locating him.
 T am searcmng for a boy who left home on August 9, last year. He is about Is years of age, height feet l0 inches dark brown hair, blue eyes, weighs about 150StO 160 pounds His mother is now very sick, and wants to hear from him. He is miner by trade and is believed to be working around the mines of Arizona. His name is Walter O'Brien, although he sometimes goes by the name of Billy O'Brien. Will you kindly help me To- cate him? ?''
 The bureau of mines endeavors to answer all inquiries, but it is some times impossible, and we would ap- preciate it if some of our readers would help us to answer these two questions
 Will you please let me know if the rock which 1 am sending under sep arate cover is ahnite. l should also like to knew what alunite is used for. and the methods of testing the same. A. n. NJ
 A. D. N. The rock which you sent was not alunite, but was orthoclase feldspar Alunite occurs in cavities of a siliceOus rock or disseminated through rock mass. Crystals are usu- ally very small. Ahlnite is potas- sium aluminium sIlphatc, although ip many cases socium is present in con siderable quantity, and where sodium is present, the value is less as it is the potassium element that gives it it's value as fertilizer. Alunite is in- fusible and turns blue with cobalt nitrate solution. Heating in a closed tube gives off water which has an acid reation It is soluble in sulphuric acid. Alunite is used ir the manufac- ture of alum, by roasting and teaching with water.
 Will you please let rno know the name of the enclosed rock and if it indicates anything. P. H. D.
 P. H. D.-The rock which you sent is an andesite, which is an igneous rock While there is no relation that can be determined to the possibility of ore deposists, there is in general close relation hctweeen iSneous rocks and ore deposits. as probably nine out of ten ore fenosits have some visible relation to a body of igneous rocks and also. a country free from igneous rocks generally has scarcity of ore deposits. The reasons for this are that practically all igneous rocks contain metals and that the conditions often are such as to allow the con- centrstion-af4 these metals While We cannot say that this applies to your particular rock, it is. in general, cor rect
 Will you kindly advise me in what parts of Arizona l may fird molvb- denum. R. l.. E.
 R. L. B.-Molybdenite is found in the following places: Gila county, in disseminated ores at Miami: Greenlee "o,,n-v in coI,r,er c'o-' 0f l..if-on Mo-