Fracture is a description of the way a mineral tends to break. It is different from cleavage and parting which are generally clean flat breaks along specific directions. Fracture occurs in all minerals even ones with cleavage, although a lot of cleavage directions can diminish the appearance of fracture surfaces. Different minerals will break in different ways and leave a surface that can be described in a recognizable way. Is the broken area smooth? Irregular? Jagged? Splintery? These are some of the ways of describing fracture. Although many minerals break in similar ways, some have a unique fracture and this can be diagnostic. The most common fracture type is conchoidal. This is a smoothly curved fracture that is familiar to people who have examined broken glass. Sometimes described as a clam-shell fracture. Quartz has this fracture type and almost all specimens that have been broken, demonstrate this fracture type very well. Another common type is subconchoidal. Similar to conchoidal, just not as curved, but still smooth. Andalusite can show this type. Uneven is a type that is basically self explanatory. It is a common type that is found in anhydrite. Unlike uneven, jagged has sharp points or edges that catch on a finger that's rubbed across the surface. Usually this indicates a metal such as copper , a metal alloy or some sulfides or oxides. Splintery is a fracture type that occurs in fibrous or finely acicular minerals and in minerals that have a relatively stronger structure in one direction than the other two. Chrysotile serpentine is a typical mineral with splintery fracture and kyanite is an example of a non-fibrous mineral that has this fracture. Earthy is a fracture that produces a texture similar to broken children's clay. It is found in minerals that are generally massive and loosely consolidated such as limonite.Fracture First Aid: Tips and Technique Fractures often occur as a result of a fall or a collision. The bones of the arms and legs are particularly vulnerable to breakage, but any bone in the body can be fractured. The type of first aid administered depends upon the kind of fracture and its location in the body. All first aid procedures for fractures include the following steps:1) If there is bleeding at the fracture site, treat the bleeding before treating the fracture.2) If excessive blood loss has led to shock, lay the victim down and treat for shock.3) Do not attempt to straighten an injured limb if it is deformed.4) Move the uninjured limb as little as possible.5) If the victim has an open fracture, with a wound on the skin surface, do not bandage tightly over the injury site. Apply a clean dressing gently over any wound.6) Contact medical personnel as soon as possible.A dislocation, which is a displacement of the bone at a joint, has many of the same symptoms as a fracture. These symptoms include possible deformity of the limb, pain and numbness immediately surrounding the injured area. If there is uncertainty as to whether the injury is a fracture or a dislocation, always treat for a fracture. See Bleeding: First Aid; First Aid Procedure: Shock Treatment.Arm or Elbow Fracture:When the lower end of the forearm is fractured, there is often little or no deformity. It is a fairly common fracture and is often mistaken for a sprained wrist. If the fracture is closed, an ice bag and limb elevation may be used to prevent further swelling. Do not let ice come into direct contact with the skin. Use ice for only 10 minutes at a time to avoid tissue damage. In the case of a severe break, do not give the victim food or drink, in case a general anesthetic is needed later.Hand or Finger Fracture:Bleeding into tissues that will cause swelling may complicate fractures of the hand and finger. Remove jewelry, especially rings, only if the removal does not aggravate the injury. If the fracture is closed, an ice bag and limb elevation may be used to prevent the swelling. Do not let ice come into direct contact with the skin. Use ice for only 10 minutes at a time to avoid tissue damage.Hip, Thigh, or Knee Fracture:Fractures of the hip may be complicated by injury to the organs of the pelvis. Do not move the victim, because there may also be spinal injuries. Do not try to straighten the fractured bone or raise the victim's legs. Do not give the victim food or drink, in case a general anesthetic is needed later. Keep the victim lying down and observe the pulse and breathing. If breathing stops, give mouth-to-mouth resuscitation. Get medical aid as soon as possible. See Artificial Respiration.Foot, Ankle, or Toe Fracture:Fractures of the foot, ankle, and toe are common injuries, often caused by a fall. They are also usually relatively minor, so before treating them, make a check for and treat any more serious injuries. It is often impossible to distinguish between fractures, dislocations, and bad sprains, the obvious sign in all three being pain and swelling. If in doubt, always treat the injury as a fracture. Do not allow the victim to attempt standing on an injured limb. Lay the victim down and get medical assistance. If it is necessary to transport the victim, a stretcher should be used. See Transporting an Injured Person.Shoulder or Collarbone Fracture:A fracture of the collarbone is usually caused by a fall on an outstretched hand or a fall on the point of a shoulder. The injury is relatively easy to recognize. The arm on the injured side is partially limp, and a swelling or deformity can be felt or seen over the fracture site. Do not give the victim food or drink as a general anesthetic may be needed later. Incline the victim's head toward the injured side to relieve pain. Move the arm on the fractured side as little as possible.Spine or Rib Fracture:A fractured spine is an extremely serious injury. If the victim is incorrectly handled, the spinal cord may be permanently damaged, resulting in paralysis. Symptoms of a fractured spine include severe pain in the back, loss of limb sensation, and loss of limb control. Do not move the victim. Rib fractures can also be very serious. If the ribs have punctured the lungs, the victim will have pain and difficulty breathing and may cough up blood or be in shock. If the ribs have penetrated the skin surface, there may be an open, sucking wound. Treat bleeding only if it is severe enough to endanger life. Treat any sucking chest wounds immediately with an airtight dressing. If the victim stops breathing, give artificial resuscitation. Get medical aid as soon as possible.
发表评论