问题 问答题 简答题

举例3种具有特殊光学效应的长石族宝石,并说明它们的鉴定特征。

答案

参考答案:

具有特殊光学效应的长石族宝石有:

1、具有月光效应的月光石;

2、具有砂金效应的月光石;

3、具有晕彩效应的拉长石;

月光石的鉴别:颜色以白色或无色中泛美丽的蓝色为佳,放大观察可见“蜈蚣”状包裹体或初始解理,折射率1.52左右,相对密度值低(2.56),在2.56重液中呈漂浮状态,正交偏光下四明四暗,锥光下可观察到二轴晶干涉图;拉长石的鉴别:颜色从无色到黄色、现灰色至深灰色,变彩效果较为明显,但多位灰蓝色、灰绿色和灰黄色,大多数为单色变彩颜色,少部分拉长石具有多色变彩颜色,硬度为6,相对密度为2.69~2.72,通常为2.70,透明、半透明至不透明,折射率为1.56~1.57,双折射率为0.009,二轴晶正光性,宝石内常含有特征的内含物,内含物由不透明的金属矿物组成,可呈针状、片状或拉长状。

填空题
阅读理解

阅读理解。

     When something goes wrong, it can be very satisfying to say, "Well, it's so-and-so's fault." or "I know

I'm late, but it's not my fault; the car broke down." It is probably not your fault, but once you form the habit

of blaming somebody or something else for a bad situation, you are a loser. You have no power and could

do nothing that helps change the situation. However, you can have great power over what happens to you if

you stop focusing on whom to blame and start focusing on how to remedy the situation. This is the winner's

key to success.

     Winners are great at overcoming problems. For example, if you were late because your car broke down,

maybe you need to have your car examined more regularly. Or, you might start to carry along with you the

useful phone numbers, so you could call for help when in need. For another example, if your colleague causes

you problems on the job for lack of responsibility or ability, find ways of dealing with his irresponsibility or

inability rather than simply blame the person. Ask to work with a different person, or don't rely on this person.

You should accept that the person is not reliable and find creative ways to work successfully regardless of

how your colleague fails to do his job well.

     This is what being a winner is all about-creatively using your skills and talents so that you are successful

no matter what happens. Winners don't have fewer problems in their lives; they have just as many difficult

situation to face as anybody else. They are just better at seeing those problems as challenges and opportunities

to develop their own talents. So, stop focusing on "whose fault it is." Once you are confident about your

power over bad situations, problems are just stepping stones for success.

1. According to the passage, winners _____.

A. deal with problems rather than blame others

B. meet with fewer difficulties in their byes

C. have responsible and able colleagues

D. blame themselves rather than others

2. The underlined word remedy in Paragraph 1 is closest in meaning to _____.

A. avoid

B. accept

C. impure

D. Consider

3. When your colleague brings about a problem, you should _____.

A. find a better way to handle the problem

B. blame him for his lack of responsibility

C. tell him to find the cause of the problem

D. ask a more able colleague for help

4. When problems occur, winners take them as _____.

A. excuses for their failures

B. barriers to greater power

C. challenges to their colleagues

D. chances for self-development

5. Which of the following is the best title for the passage?

A. A Winner's Secret.

B. A Winner's Problem.

C. A Winner's Opportunity.

D. A Winner's Achievement.