TABLE I. FOR DETERMINATION OF MINERALS. 429 



The following hints may be of service to the beginner in 

 the science, by enabling him to overcome a difficulty in the 

 outset, arising from the various forms and appearance of the 

 minerals quartz and limestone. Quartz occurs of nearly 

 every color, and of various degrees of glassy luster to a dull 

 stone without the slightest glistening. The common grayish 

 cobble stones of the fields are usually quartz, and others 

 are dull red and brown ; from these there are gradual 

 transitions to the pellucid quartz crystal that looks like glass 

 itself. Sandstones and freestones are often wholly quartz. 

 and the seashore sands are mostly of the same material. It is 

 therefore probable that this mineral will be often encountered 

 in mineralogical rambles. Let the first trial of specimens 

 obtained be made with a file or the point of a knife, or some 

 other means of trying the hardness ; if the file makes no im- 

 pression, there is reason to suspect the mineral to be quartz ; 

 and if on breaking it, no regular structure or cleavage plane 

 is observed, but it breaks in all directions with a similar 

 surface and a more or less vitreous luster, the probability is 

 much strengthened that this conclusion is correct. The 

 blowpipe may next be used ; and if there is no fusion pro- 

 duced by it, when carefully Used on a thin splinter, there can 

 be little doubt that the specimen is in fact quartz. 



Carbonate of lime (calc spar, including limestone,) is 

 another very common species. If the mineral collected is 

 rather easily impressible with a file, it may be of this species : 

 if it effervesces freely when placed in a test-tube containing 

 dilute muriatic acid, and is finally dissolved, the probability 

 of its being carbonate of lime is increased : if the blowpipe 

 produces no trace of fusion, but a brilliant light from the 

 fragment before it, but little doubt remains on this point. 

 Crystalline fragments break with three equal oblique 

 cleavages. 



Familiarized with these two Protean minerals by the trials 

 aere alluded to, the student has already surmounted the prin- 

 cipal difficulties in the way of future progress. Frequently 

 me young beginner, who has devoted some time to collecting 

 all the different colored stones in his neighborhood, on pre- 

 senting them for names to some practised mineralogist, is a 

 little disappointed to learn that, with two or three exceptions, 

 his large variety includes nothing but limestone and quartz. 

 He is perhaps gratified, however, at being told that he may 

 call this specimen yellow jasper, that red jasper, anothei 



