Frequently Asked Questions
What is TDW. or TSW.? =
Total Diamond/Stone Weight.
RBC = Round Brilliant Cut
USPC = USA dollars per carat
DIAMOND
GRADES
COLOUR
D E F Colourless
G H I J Near
Colourless
K L M Faint Yellow
N O P Q R Very Light Yellow
S
T U V W X Y Z Light - Dark Yellow
CLARITY (All clarity grading
is performed at 10-times magnification)
Flawless FL
Internally
Flawless IF
Very Very Slight Inclusions VVS1 - VVS2
Very
Slight Inclusions VS1 - VS2
Slight Inclusions (near eye clean)
SI1 - SI2 - SI3
Included (Eye Visible) I1 - I2 - I1
One
pitfall to avoid when shopping for clarity is the "clarity-enhanced"
diamond. This is an artificial process used to "fix" the flaws on an
otherwise good stone. Although a clarity-enhanced diamond can look
nearly flawless (in some cases, it is impossible to detect the
enhancement), it is intrinsically worth as much as a flawed stone.
Furthermore, the durability is nowhere that of pure diamond. Be sure to
confirm with your jeweller that the stone you are considering is not
clarity-enhanced, and be sure to double-check this fact on the
certificate. If you do not receive a certificate with your stone, ask
the jeweller to state that the diamond is not clarity-enhanced on the
appraisal.
What is Rhodium Plating?
Rhodium is
a platinum group metal of high value, typically twice the price of
platinum and 3 to 4 times the price of gold. It is a hard, white, highly
reflective metal and is predominantly used to enhance the whiteness and
reflectivity of white gold jewellery.
Why Rhodium Plate?
Rhodium plating is a technique
often used to plate white gold rings and or settings, giving them high
reflectivity and so enhancing the "brilliant" appearance of diamond.
Rhodium is also chemically inert and will withstand corrosive attack.
For this reason, it is often used on white gold jewellery to give extra
protection during everyday use.
Will
Rhodium Plate Wear?
First, we have to look at the
definition of "white gold". Many manufacturers use white gold alloys
that contain only small additions of either nickel or palladium as a
bleacher, which results in a colour that is actually best described as
pale yellow or greyish yellow. Because the whitening additions are
present, the gold alloy is described as "white" when perhaps "straw"
would be a better description.
To make the ring and or setting
look more desirable, it is rhodium plated and so it has a beautiful
white reflective surface. The problem with this is when the plated
jewellery has been worn over a period of time and undergoes wear.
Rhodium is usually only plated to a thickness of a micron or so (one
micron = 1/1000th of a millimeter). This will be removed over time,
exposing the straw colour of the original "white" gold alloy underneath.
The contrast between the remaining rhodium plate and the original white
gold is very noticeable and makes the jewellery look worn and poor.
This results in you having to make frequent trips to your jeweller to
have your jewellery re-plated.
We rhodium plate our white gold
jewellery to give you the optimum color and reflective surface to
enhance the diamond and your jewellery, but here's where we're different
and stand out from the crowd. You can choose to use a true white alloy
to start with and plate this. Because of the minimal contrast between
our super white gold alloy (Platinum and Palladium alloy - Pt. Pd.
Alloy) and the rhodium plating, when wear occurs in highlighted areas
and rhodium is removed, it is far less noticeable than with most other
white gold jewellery. The base alloy is not as reflective but is a good
white colour, making wear and tear less noticeable. This greatly
increases the time between re-rhodium plating and keeps your jewellery
looking great. In some cases our white gold Pt. Pd. alloy colour
is preferred by some of our customers, removing the need for rhodium
plating completely.
Be aware that
some jewellers sell their white golds as “Platinumised White Gold”, but alloy actually only has 3% platinum, therefore it should be
called / sold as “White Gold – Platinum Alloy” to avoid confusion and or
misleading customers.
What is

Palladium, along with platinum, rhodium,
ruthenium, iridium and osmium form a group of elements referred to as
the platinum group metals (PGMs). PGMs share similar chemical
properties, but palladium has the lowest melting point and is the least
dense of these precious metals. When palladium is at room temperature
and atmospheric pressure, it can absorb up to 900 times its own volume
of hydrogen, which makes palladium an efficient and safe storage medium
for hydrogen and hydrogen isotopes.
Palladium is also tarnish
resistant, electrically stable and resistant to chemical erosion as well
as intense heat. Palladium itself has been used as a precious metal in
jewellery since 1939, as an alternative to platinum or white gold. This
is due to its naturally white properties, giving it no need for rhodium
plating. It is slightly whiter, much lighter and about 12% harder than
platinum. Similar to gold, palladium can be beaten into a thin leaf form
as thin as 100 nm (1/250,000 in).
Like platinum, it will develop
a hazy patina over time. Unlike platinum, however, palladium may
discolour at high soldering temperatures, become brittle with repeated
heating and cooling, and react with strong acids. It can also be used as
a substitute for nickel when making white gold. Palladium is one of the
three most popular metals used to alloy with gold, making white gold.
(Nickel and silver can also be used.) Palladium-gold is a more expensive
alloy than nickel-gold, but it's naturally hypoallergenic and holds its
white colour better.
When platinum was declared a strategic
government resource during World War II , many jewellery bands were made
out of palladium. As recently as September 2001, palladium was more
expensive than platinum and rarely used in jewellery also due to the
technical obstacle of casting. However the casting problem has been
resolved and its use in jewellery has increased because of a large spike
in the price of platinum and a drop in the price of palladium.
Prior
to 2004, the principal use of palladium in jewellery was as an alloy in
the manufacture of white gold jewellery, but, beginning early in 2004
when gold and platinum prices began to rise steeply, Chinese jewellers
began fabricating significant volumes of palladium jewellery. Johnson
Matthey estimated that in 2004, with the introduction of palladium
jewellery in China, demand for palladium for jewellery fabrication was
920,000 ounces, or approximately 14% of the total palladium demand for
2004 - an increase of almost 700,000 ounces from the previous year.
This
growth continued during 2005, with estimated worldwide jewellery demand
for palladium of about 1.4 million ounces, or almost 21% of net
palladium supply, again with most of the demand centered in China. The
popularity of Palladium jewellery is expected to grow in 2009 as the
world's biggest producers embark on a joint marketing effort to promote
Palladium jewellery worldwide

18ct. Gold Alloys





White Gold vs Platinum.
White
gold certainly resembles platinum in many ways, but inside, it's still
gold. In fact, it's up to 75 percent yellow gold; the white colour comes
from the addition of white-metal alloys such as nickel, silver and
palladium. Often, white gold is rhodium plated to imitate the look of
platinum. The addition of alloys, such as nickel, can alter the gold's
normal properties. For instance, nickel occasionally presents a problem
for those with sensitive skin, even though the presence of nickel makes
the white gold harder and less likely to scratch. The addition of
palladium can create a whiter look, closer to that of platinum, and the
metal causes fewer skin irritations, but palladium can be pricey, which
decreases affordability.
By contrast, platinum is up to 95
percent pure (some alloys are added to make it more scratch-resistant
and less likely to bend). Platinum is hypoallergenic and is the
strongest metal used in jewellery, and one that outlasts gold. This
purity is a significant factor in its higher price point. Fourteen-karat
gold, for example, contains only 58 percent pure gold. Platinum is also
about 60 percent heavier than gold, a heft many find desirable.
Close
inspection reveals that white gold and platinum aren't really the same
hue. White gold betrays its composition with a yellowish tint while
platinum has a natural white lustre. Untreated, white gold gives off a
soft, warm tone, but rhodium plating can create a shinier, truer white
appearance if desired. Keep in mind that the plating will need annual
replacement. White gold and platinum both make beautiful jewellery, but
knowing exactly how they differ will ensure a purchase that best meets
your jewellery needs.