WorldWide Drilling Resource

Barite receives its name from the Greek word "barys" , which means "heavy." This name is in response to barite's specific gravity of 4.5, which is quite high for a nonmetallic mineral. Specific gravity is the ratio between the density of an object, and a reference substance, such as water, meaning barite is 4.5 times more dense than water. This makes barite suitable for a wide range of industrial, medical, and manufacturing uses. Most barite produced is used as a weighting agent in drilling muds. These high-densi ty m u d s a r e pumped down the drill stem, then exit through the cutting bit, and return to the surface between the drill stem and the wall of the well. This flow of fluid cools the drill bit, and the high-density barite mud suspends the rock cuttings produced by the drill, carrying them up to the surface. Barite is used as a pigment in paints and as a weighted filler for paper, cloth, and rubber. The paper used to make some playing cards has barite packed between the paper fibers, giving the paper a very high density, which allows the cards to be dealt easily to players. Barite is also used as a weighting filler in rubber to make mud flaps for trucks. Biotite is a name used for a large group of black mica minerals commonly found in igneous and metamorphic rocks. They can vary in chemical composition, but are all sheet silicate minerals with very similar physical properties. These minerals generally cannot be distinguished from one another without a laboratory using optical, chemical, or x-ray analysis. Even with little experience, a person will be able to recognize biotite on sight. It is black with per- fect cleavage and luster on the cleavage faces. When biotite is separated into thin sheets, the sheets are flexible, but will break upon severe bending. When held up to the light, the sheets are transparent to translucent with a brown, gray, or greenish color. Biotite is hard to clean because if washed, it will absorb water and start to break. The best way to clean it is with a dry electric toothbrush. Biotite has been known to cause excitement when misidentified by inexperienced gold panners. A few tiny flakes of biotite swishing in a gold pan can produce bright bronze-colored reflections in the pan when struck by sunl ight. These reflections can fool the panner into thinking he has found gold. If the panner regains his composure, removes one of these flakes from the pan, and pokes it with a pin, the biotite flake will break. Biotite is a very poor conductor of heat and electricity, and is used as an insulator for various electrical products and semiconductors. It is used as a filler and extender in paints, addi t ive in drilling muds, mold-release agent in rub- ber products, and a nonstick surface coating on asphalt shingles and rolled roofing. It is also used in the potassium- argon and argon-argon methods of dat- ing igneous rocks. 4< /*2'3* "& > > > > ,'< ? /2+ '6* /3+6 /3+6 ')1/3- " " !8=2+ /7843 4* 4* ')1/3- !+8 5)7 !8'3*'6* $'2:+ 9((+6 6':+2 $'2:+ 9((+6 !+'87 9((+6 $'2:+ 37+687 #6+8.'3+ $'2:+ 37+687 $'2:+ !56/3- ! ! $'2:+ 4:+6 '71+8 ? !;/:+2 ')1/3- ? !+6/+7 ? !+6/+7 ? !+6/+7 ? !+6/+7 ? !+6/+7 ? !+6/+7 < /3+6 < /3+6 < /3+6 < /3+6 < /3+6 6/)+7 !9(0+)8 "4 .'3-+ %/8.498 48/)+ !@ @ < < < < < The World of Minerals Minerals Barite rose. 49 WorldWide Drilling Resource ® OCTOBER 2017