时间:2019-02-25 作者:英语课 分类:双语有声阅读


英语课
Topaz
 
Topaz is a hard, transparent 1 mineral. It is a compound of aluminum 2, silica, and fluorine. Gem 3 topaz is valuable. Jewelers call this variety of the stone "precious topaz". The best-known precious topaz gems 4 range in color from rich yellow to light brown or pinkish red. Topaz is one of the hardest gem minerals. In the mineral table of hardness, it has a rating of 8, which means that a knife cannot cut it, and that topaz will scratch quartz 5.
 
The golden variety of precious topaz is quite uncommon 6. Most of the world's topaz is white or blue. The white and blue crystals of topaz are large, often weighing thousands of carats. For this reason, the value of topaz does not depend so much on its size as it does with diamonds and many other precious stones,where the value increases about four times with each doubling of weight.The value of a topaz is largely determined 7 by its quality.But color is also important: blue topaz, for instance, is often irradiated to deepen and improve its color.
 
Blue topaz is often sold as aquamarine and a variety of brown quartz is widely sold as topaz. The quartz is much less brilliant and more plentiful 8 than true topaz. Most of it is a variety of amethyst 9: that heat has turned brown.
 

黄水晶
 
黄水晶是一种坚硬、透明的矿物质。 它是铝、硅和氟的化合物。 黄水晶宝石价值不菲。珠宝商把这种石头称为"黄玉"。最出名的黄玉有各种颜色如深黄色、淡棕色、浅红色等。黄水晶是最坚硬的宝石矿中的一种。 在矿石硬度表上,它的硬度为 8,这表明刀子不能割开它而它可在石英上划痕。 金黄色的黄玉品种非常罕见。 世界上大多数的黄水晶是白色或蓝色的。 这些白色或蓝色的黄水晶晶体很大,常常有数千克拉重。 由于这个原因,黄水晶的价值不像钻石和许多其它宝石那样主要依赖于其大小,重量翻一番价值即上升约四倍。 黄水晶的价值很大程度上取决于其品质,但颜色也很重要。 举例来说,蓝色的黄水晶常需放射处理以加深和改善其颜色。 蓝色的黄水晶常被作为海蓝宝石出售,许多种棕色石英被当作黄水晶广为贩卖。 石英光亮度远小于黄水晶,矿藏储量也远较黄水晶丰富。 大多数石英是一种紫水晶,高温使其变为棕色。


adj.明显的,无疑的;透明的
  • The water is so transparent that we can see the fishes swimming.水清澈透明,可以看到鱼儿游来游去。
  • The window glass is transparent.窗玻璃是透明的。
n.(aluminium)铝
  • The aluminum sheets cannot be too much thicker than 0.04 inches.铝板厚度不能超过0.04英寸。
  • During the launch phase,it would ride in a protective aluminum shell.在发射阶段,它盛在一只保护的铝壳里。
n.宝石,珠宝;受爱戴的人 [同]jewel
  • The gem is beyond my pocket.这颗宝石我可买不起。
  • The little gem is worth two thousand dollars.这块小宝石价值两千美元。
growth; economy; management; and customer satisfaction 增长
  • a crown studded with gems 镶有宝石的皇冠
  • The apt citations and poetic gems have adorned his speeches. 贴切的引语和珠玑般的诗句为他的演说词增添文采。
n.石英
  • There is a great deal quartz in those mountains.那些山里蕴藏着大量石英。
  • The quartz watch keeps good time.石英表走时准。
adj.罕见的,非凡的,不平常的
  • Such attitudes were not at all uncommon thirty years ago.这些看法在30年前很常见。
  • Phil has uncommon intelligence.菲尔智力超群。
adj.坚定的;有决心的
  • I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
  • He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。
adj.富裕的,丰富的
  • Their family has a plentiful harvest this year.他们家今年又丰收了。
  • Rainfall is plentiful in the area.这个地区雨量充足。
n.紫水晶
  • She pinned a large amethyst brooch to her lapel.她在翻领上别了一枚大大的紫水晶饰针。
  • The exquisite flowers come alive in shades of amethyst.那些漂亮的花儿在紫水晶的映衬下显得格外夺目。
学英语单词
abusiveness
aestisilval
Akmyane
antenna for super high frequency
better-looking
bettie
by-pass-valve
central portion
chemical ash
closed jet tunnel
cocarboxylases
complete diabetes insipidus
cost-centre
crash-landings
crista supinatoria
cross furring ceiling
Cytophaga
defense intelligence agencies
Dehio's butter
dentil
DEROTREMES
diammine tin chloride
Dimastigamoebidae
directive therapy
end yoke type propeller shaft
enioy
fowling
full word instruction
game room
give somebody a ring
global alignment
glomerulomegaly
goes into particulars
gotten possession of
guided missile submarine
h.e.p.
hakewill
Hexemalcalcium
high pitch regulator
high-voltage switch
homogeneous sill
honorous
horror films
inadvertents
integumentary embryo
interference ripple mark
juniper berriess
Kull's method
land board
liturge
lobelia siphiliticas
lyrella perplexoides
Maisonneuve's bandage
make heavy weather of something
matrix-managements
morescoes
mortgageor
mrozek
Nabothian menorrhagia
nanobelt
neothalamus
noppe
noses about
octahedral sulfur
optoelecric coupling
oscillating coil
ovarian fossa
physico-chemical
pointillist
popularisms
postterm pregnancy
prepaid discount account
quadruple bond
ramen profitable
Republicunts
resin kettle
roll-type downcoiler
RRAM
semi portal
Serengeti Plain
Sharpey's fibres
sheathed vessel
sticky shale
stoichiometry
stress-induced crystallization
taenioglossate
tectorial cell
tenalgia crepitans
tezla
thiazolidinedione
timber derrick
trou-de-loup
us up
vehicle radiator cap
Veratrum viride
virus signature
walk rearrangement
well-pit
Wheat-rust
Wolfit
xylenolcarboxylic acid
zero-order Bessel function