what is a mineral?
a naturally occurring, inorganic solid that has a characteristic chemical composition and a definite crystal structure
what is a rock?
an aggregate of two or more minerals exhibiting no crystal structure
list the spectral colors in order of least energized to most energized. when mixed, what type of light is the result?
roygbiv. white light
what is the gem cutter's main goal when planning the fashioning of a rough gemstone?
to produce the most valuable gem
list the three main parts of a faceted gem
crown, girdle, pavillion
name the crystal system that is most symmetrical and produces singly refractive gemstones. give an example of a colored gemstone from this sytem.
cubic- garnet
explain the difference between an inclusion and a blemish. give an example of each
blemish: damage to the surface of the gem. ex. chip
inclusion: damage inside the gem. ex. feather
name the 5 determining considerations in colored stone clarity grading
nature, size, position, number, color/relief
list at least 3 factors that constitute a gem
durability, tradition, & rarity
in gemstone lore, it is said emperor nero is said to have viewed the heat and violence of gladiator combat through the cool clarity of the gem
emerald
list the three types of rocks found in the earth's crust
igneous, sedimentary, metamorphic
light moving from a less dense medium to a denser medium will slow down and be bent. this is called:
refraction
list the two gems that form in the earth's mantle
diamond & peridot
in mining, secondary deposits are gems found away from their primary source. list the two types of secondary deposits
eluvial & alluvial
the two most abundant elements in the earth's crust are
silicon & oxygen
the first basic color you observe of a gemstone is the
hue
a gemstone with the crystal structure that does not allow light to pass through it has
opaque transparency
what is the most common break for a transparent colored gemstone?
conchoidal
the light to dark color sensation is divided into a
tone scale
the refractometer measures the
critical angle of light
a low saturation that looks brownish has a gem color of
orange
a gemstone that is stimulated by ultraviolet radiation and emits visible light is
fluorescing
using a microscope or loupe, a gemologist assigns the clarity grade at
10x magnification
which of the following transparent gemstones do not show pleochroism?
almandite, garnet
a gemstone's resistance to breaking and chipping is known as it's
toughness
peridot is considered
idiochromatic
name the type of mining deposit that delivers the highest yield
pipe deposit
the spectroscope is a tool used to examine how light is
absorbed in a gemstone
which of the following is most important for the value of an emerald beryl?
color
what is an example of an organic gem?
amber
a mineral that does not have a regular crystal structure is called
amorphous
cat's eye chrysoberyl displays a phenomenon called
chatoyancy
when examining the clarity of a gemstone, it is important to first
clean the stone
if a gem blinks between light and dark in full rotation on a polariscope it is
double refractive
star sapphire is a variety of this species
corundum
the quantity of light that is allowed to pass through a gemstone is called it's
transparency
which of the following gemstones can scratch corundum?
diamond
if the color of a gem will fade when it is exposed to sunlight. this refers to its
stability
this bi-colored variety of this gemstone is named for the fruit, watermelon
tourmaline
in what gems lore was it supposed to keep you from becoming drunk?
amethyst
which are factors affecting mining and recovery of gemstones?
climate, politics, accessibility
specific gravity is an important factor when figuring
weight estimation
selective abortion is the reason we can see
color in a gem
one of the most often seen transition elements causing color in gemstones is
chromium
color is gems is described in what order?
tone, saturation, hue
part of the original crystal surface that remains unpolished on the finished gemstone is called?
a natural
in the united states, which form and spelling of the word is equated with gem weight?
carat
subdivisions of a species based on color, transparency, and/or phenomena is the definition of a
variety
80% of the earth's volume is represented by
the mantle
rocks that form from the physical and/or chemical weathering of existing rocks are called
sedimentary
an emerald would fall into which colored stone clarity type?
type 3
a workable deposit of gem minerals with economic potential is called a
placer
this island nation is an important source for colored stones
madagascar
the shine of a gem in reflected light is considered its
luster
if a gem shows two pleochroic colors when viewed through the dichroscope, it is called
dichroic
when ground up for medicine, the red color of this gem was said to cure fever, while the yellow color cured jaundice
garnet
the way in which a gem normally crystallizes is called its
crystal habit
in 1947, the diamond cartel DeBeers came up with this marketing slogan
a diamond is forever
most phenomenal gems are cut into this shape to enhance their optical effect
cabochon
TF: allochromatic is a term used to describe a gem that its color is caused by elements in its own chemical composition
true
TF the luster for most transparent gems is vitreous
true
TF a gem with the hardness of 8 can only scratch another gem with hardness of 7 or less
false
TF stability is the ability of a gemstone to resist forms of deterioration
true
TF blocking is a cutting term used to describe when the cutter adds the star and bezel facets to a gem
false
tf the definition of a covalent bond is where atoms join to form a molecule that shares electrons
true
tf in ruby lore, it was thought rubt would soothe the eyes
true
tf the term anisotropic describes a gem that is singly refractive
false
tf type 1 clarity gemstones often form with very eye visible inclusions
false
tf a dichroscope is a tool that shows if a gem is pleochroic
true
tf hardness is important in jewelry as it determines what can be worn for a lifetime
true
tf the first rocks on earth were igneous rocks
true
tf shaft mining is labor intensive but very high yield
false
tf in doubly refractive gems, an axis of singly refraction is called its optic axis
true
tf contact metamorphism is large scale metamorphism, such as mountain building
false
tf extrusive and intrusive are types of metamorphic rocks
false
tf ansiotropic is a term meaning doubly refractive
true
tf corundum forms in the tetragonal crystal system
false
tf windowing is caused by the light leaking through the back of a gemstone
true
tf type 3 clarity includes gems that form with many inclusions that are usually eye visible
true
tf an alluvial deposit is described as a deposit where gems erode from their source rock and are subject to gravitational movement and accumulation
false
tf in cutting girdling us roughing out the gem's shape
true
tf misshapen facets, irregular facet junctions and alignment between crown and pavillion are all aspects of symmetry
true
tf garnets will blink when viewed in rotation in the polariscope
false
the wax coated stick used to hold gems for cutting and polishing is called a dop
true
tf pegmatites often rich in volatile magma and mineral building elements cools slowly allowing for large crystal growth
true
tf seeds were generally uniform, so they were used as a standard of measure when weighing something small
true
tf hydrothermal deposits are special because they can have combinations of elements not found elsewhere
true
tf at one time, it was believed that the fourth finger on the left hand contained a vein, vena amoris, or vein of the heart that led directly to the heart
true
tf a gem species is a subdivision based on color, transparency, and/or phenomena
false
tf specific gravity is a measurement of weight and will change with the size of the gem
false
tf romance and love is the emotional catalyst that often forms our bond with jewelry and gems
true
tf if the refractometer scale is all shadow then the gem is considered OTC or off the chart
false
tf intaglio is a term used to describe a type of carving that is raised above the surface of a gem
false
tf quartz is made up of the earth's two most abundant elements
true
Approximately how much peridot is in the mountains of Pakistan?
10 million carats worth ($50-80/ct)
What is the name of the regulations created to control the sale of conflict diamonds?
Kimberley Process Certification Scheme
Which of the following are uses of azurite?
Copper mining and prospecting, Jewelry and ornamentation, Pigmentation
What are the names of the two forms of jade?
Nephrite and Jadeite
What diamond was the Heart of the Ocean from the movie Titanic based on?
the Hope Diamond
Through what process were synthetic diamond sheets that were put on screwdrivers and tweezers made?
Through what process were synthetic diamond sheets that were put on screwdrivers and tweezers made?
The Hope diamond that Harry Winston bought weighed how many carats?
45.52 ct
How does lapis lazuli form?
Contact metamorphism
Name two of the four main deposits where Montana sapphires are mined.
Yogo Gulch, Rock Creek, The Missouri River and Dry Cottonwood Creek
What era introduced white jewelry?
Edwardian
What percentage of Europe's art was looted by the Nazis?
20%
In the movie, "Uncut Gems", Adam Sandler's character acquires what rare gem from the Welo mine?
Ethiopian Black Opal
What are the phenomena that often occur in moonstone?
Adularescence and chatoyancy
In regards to the Antwerp Diamond Heist; what was the name of Leonardo's gang?
The School of Turin
what is used as a stimulant for diamond
colorless zircon
when isomorphous replacement
...