Avoid Fake Silver Bars and Gold Bullion

1
Avoid Fake Silver Bars and Gold Bullion

Presenter Notes
Avoid Fake Silver Bars and Gold Bullion

2
Introduction

• Gold and silver have been used as a store of
  value and a widely accepted currency for
  thousands of years. For as long as gold and
  silver have had value, then unscrupulous people
  have been making fakes. And for as long as fakes
  have been made, then tests to identify those
  fakes have been devised ranging from a simple
  bite into gold coins, to the discovery of the
  principal of specific gravity, to the latest high
  tech laboratory analysis.

Presenter Notes
Gold and silver have been used as a store of
value and a widely accepted currency for
thousands of years. For as long as gold and
silver have had value, then unscrupulous people
have been making fakes. And for as long as fakes
have been made, then tests to identify those
fakes have been devised ranging from a simple
bite into gold coins, to the discovery of the
principal of specific gravity, to the latest high
tech laboratory analysis.

3
Specific Gravity

• Specific gravity testing came about some 250
  years before the birth of Christ, when Greek King
  Heiro II commissioned Archimedes to find out if a
  goldsmith had cheated him in the crafting of a
  new crown. The problem was solved when
  Archimedes noticed that the amount of water
  displaced by an object when it is immersed in
  water is equal to its volume. He realized that
  objects of the same mass would displace differing
  amounts of water depending on their density, or
  specific gravity (SG). Archimedes is claimed to
  have yelled Eureka upon the discovery, and the
  kings suspicions about the goldsmith were then
  proven to be well-founded.

Presenter Notes
Specific gravity testing came about some 250
years before the birth of Christ, when Greek King
Heiro II commissioned Archimedes to find out if a
goldsmith had cheated him in the crafting of a
new crown. The problem was solved when
Archimedes noticed that the amount of water
displaced by an object when it is immersed in
water is equal to its volume. He realized that
objects of the same mass would displace differing
amounts of water depending on their density, or
specific gravity (SG). Archimedes is claimed to
have yelled Eureka upon the discovery, and the
kings suspicions about the goldsmith were then
proven to be well-founded.

4
Specific Gravity

• Upon the discovery of specific gravity, faking
  gold objects with exact dimensions became more
  difficult as few substances are as dense as gold,
  which has an SG of 19.3. This means gold weighs
  19.3 times as much as the same volume of water.
  Platinum is slightly denser than gold. During
  some periods of history platinum has been alloyed
  with lighter metals to fake gold when the price
  of platinum was a lot less than gold. Right now
  platinum is a little more expensive than gold,
  making that opportunity uneconomic.

Presenter Notes
Upon the discovery of specific gravity, faking
gold objects with exact dimensions became more
difficult as few substances are as dense as gold,
which has an SG of 19.3. This means gold weighs
19.3 times as much as the same volume of water.
Platinum is slightly denser than gold. During
some periods of history platinum has been alloyed
with lighter metals to fake gold when the price
of platinum was a lot less than gold. Right now
platinum is a little more expensive than gold,
making that opportunity uneconomic.

5
Faking Gold with Tungsten

• However, there is another metal which is very
  nearly the same density as gold and relatively
  cheap. That metal is tungsten. Up until recent
  times it was difficult to create convincing fakes
  of gold with tungsten because tungsten is very
  brittle, so it is difficult to emboss or stamp,
  unlike gold which is very soft. Unfortunately
  the Chinese have recently used modern machining
  techniques to make gold-coated tungsten fakes of
  many different bullion and coin products. These
  fakes can be found all over Chinese trade sites
  on the internet, and they appear in the news when
  westerners discover they have been defrauded.
  Some of the fakes are so perfect the
  manufacturers can command asking prices that are
  nearly half the equivalent gold value of the real
  item, even though the fakes only contain a few
  dollars worth of gold.

Presenter Notes
However, there is another metal which is very
nearly the same density as gold and relatively
cheap. That metal is tungsten. Up until recent
times it was difficult to create convincing fakes
of gold with tungsten because tungsten is very
brittle, so it is difficult to emboss or stamp,
unlike gold which is very soft. Unfortunately
the Chinese have recently used modern machining
techniques to make gold-coated tungsten fakes of
many different bullion and coin products. These
fakes can be found all over Chinese trade sites
on the internet, and they appear in the news when
westerners discover they have been defrauded.
Some of the fakes are so perfect the
manufacturers can command asking prices that are
nearly half the equivalent gold value of the real
item, even though the fakes only contain a few
dollars worth of gold.

6
Faking silver with base metals

• In the case of silver, the manufacturers of
  counterfeits have a greater choice of metals to
  use for faking silver bars and coins and still
  achieve the correct weight and dimensions. Base
  metal alloys with any range of combinations of
  copper, tin, lead, zinc and iron can be used as
  an inner core to counterfeit silver bullion and
  coins with a pure silver shell, coating or
  plating at the surface.

Presenter Notes
In the case of silver, the manufacturers of
counterfeits have a greater choice of metals to
use for faking silver bars and coins and still
achieve the correct weight and dimensions. Base
metal alloys with any range of combinations of
copper, tin, lead, zinc and iron can be used as
an inner core to counterfeit silver bullion and
coins with a pure silver shell, coating or
plating at the surface.

7
Coating and plating fakes

• The coating or plating of gold and silver used in
  the manufacture of fakes with perfect weight,
  dimension and appearance is usually thick enough
  to fool X-ray Fluorescence (XRF) testing, which
  is only capable of penetrating a few tens of
  microns beneath the surface. Nowadays it is
  becoming increasingly common for dealers to
  refuse to buy gold and silver bullion, bars and
  coins from the public without undertaking some
  sort of destructive test. This may entail
  attempting to scratch off any surface plating, or
  even cutting into the metal itself.

Presenter Notes
The coating or plating of gold and silver used in
the manufacture of fakes with perfect weight,
dimension and appearance is usually thick enough
to fool X-ray Fluorescence (XRF) testing, which
is only capable of penetrating a few tens of
microns beneath the surface. Nowadays it is
becoming increasingly common for dealers to
refuse to buy gold and silver bullion, bars and
coins from the public without undertaking some
sort of destructive test. This may entail
attempting to scratch off any surface plating, or
even cutting into the metal itself.

8
Another property sound velocity

• However, there remains another physical property
  that can differentiate between real gold and
  silver bullion products and counterfeits, without
  having to destroy them. That property is the
  velocity that sound waves travel through metal.
  Metals have a range of sound velocities depending
  on both their density and hardness. Even though
  tungsten and gold have very similar densities,
  the great difference in their hardness results in
  a sound velocity of 3240 m/s for pure gold and
  5400 m/s for tungsten. The sound velocity for
  silver is 3620 m/s and the alloys used to fake
  silver typically register sound velocities higher
  than 4000 m/s.

Presenter Notes
However, there remains another physical property
that can differentiate between real gold and
silver bullion products and counterfeits, without
having to destroy them. That property is the
velocity that sound waves travel through metal.
Metals have a range of sound velocities depending
on both their density and hardness. Even though
tungsten and gold have very similar densities,
the great difference in their hardness results in
a sound velocity of 3240 m/s for pure gold and
5400 m/s for tungsten. The sound velocity for
silver is 3620 m/s and the alloys used to fake
silver typically register sound velocities higher
than 4000 m/s.

9
Use ultrasound to test silver and gold bars and
bullion

• The way to test silver bars and gold bullion for
  sound velocity is by using ultrasound.
  Ultrasound testing of silver and gold for sound
  velocity is affordable and can be done
  conveniently in your own home. To find about the
  technology and how it can save investors and
  dealers from being defrauded by counterfeit gold
  and silver, visit http//testyourgold.com/.

Presenter Notes
The way to test silver bars and gold bullion for
sound velocity is by using ultrasound.
Ultrasound testing of silver and gold for sound
velocity is affordable and can be done
conveniently in your own home. To find about the
technology and how it can save investors and
dealers from being defrauded by counterfeit gold
and silver, visit http//testyourgold.com/.