Salt cementation was an ancient technique for separating gold and silver. It involved heating together an alloy of gold and silver with salt, clay or brick dust, and urine. Chemical reactions would occur that produced hydrochloric acid and chlorine, causing the silver to separate out as silver chloride. This left the gold in a purer state that was suitable for currency, usually 18k or higher purity. The technique was important for early civilizations to refine precious metals, though it is no longer widely used due to more advanced modern refining methods.

1. Salt Cementation &
Gold Extraction
An ancient refining technique that separates silver
and gold

2. Gold as it Naturally Occurs
• As any professional miner could tell you, gold rarely
appears in its pure form under the earth’s crust.
• During excavation, gold is usually found with silver
– forming an alloy known as electrum.
• Gold and silver share a lot of chemical similarities, so
they alloy together easily.

3. Separating Gold and Silver
• In ancient times, people needed a
way to standardize the purity of the
gold and silver they were using for
currency.
• Alloys with variable amounts of gold,
silver, and could not hold up to circulation.
• As a result, one of the earliest precious metal
refining techniques was created: gold parting via
salt cementation.

4. Ingredients for Salt
Cementation
• Modern precious metal refining is a sophisticated
science, but salt cementation is relatively easy.
• The tools required for the process include:
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Gold/silver alloy
Burnt clay or old brick dust
Salt
Urine (bear with us, please – this is a very antiquated
refining technique)

5. Gold Parting Via Salt
Cementation
• Once all the ingredients are heated in a sealed
jar, the gold purity vastly improves within 24 hours
– usually greater than 18k.
• The recipe for salt cementation
sounds like a random
hodgepodge of junk,
but it’s a complex
chemical reaction.

6. The Process
• When heated in the presence of silica and alumina
(found in the clay/brick dust), salt breaks down to
form hydrochloric acid and chlorine.
• Remember the urine (who could forget)? The acidity
from urine helps the above reaction happen faster.
• The hydrochloric acid interacts with the silver in the
alloy to create silver chloride, which separates from
the gold.
• This reaction is quite volatile, which is why the container
needs to be sealed.

7. The Results
• Now that the two elements are
separated, you’re left with pure
gold.
• The silver chloride can be
recaptured and converted back
into elemental silver.
• This ancient technique is no longer widely used, but
it was important for early civilizations to create
pure gold for trade and craft.

8. About MGS
Manhattan Gold & Silver (MGS) is a precious metals refiner that has been based in
Manhattan’s historic Diamond District since 1985. We are a B2B company that
buys and recycles precious metal scraps that accumulate in other businesses.
We serve:
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Jewelers
Pawnbrokers
Dentists
The industrial sector
Antique dealers
Machinists
Domestic mining
And more!
• MGS also creates charts, calculators, and other online tools for our customers to
use.
• Try our Precious Metals Prices app, which lets you monitor the real-time precious metals
market situation from anywhere, right from your iPhone, iPad, or Android device.

9. Recycle your Precious
Metals for Profit
• MGS accepts gold, silver, platinum, and palladium.
• Payouts are based on the London Fixing.
• Up to 99% payout (among the highest in the US)
• Up to 98.5% for gold brought in for hand testing.
• Not in NYC? Ship us your precious metals using our Ship &
Sell service which offers:
• Same day wired payment (once lot is received)
• Discounted, insured shipping
• Payout calculator

10. Connect with MGS
• For amazing facts, history and news, read our gold and precious metals blog.
• Join the conversation about precious metals on the MGS page on Facebook.
• Follow gold, silver, and other precious metal trends at the MGS Twitter account.
• Circle MGS on Google+ to hear our latest updates.
• If you do business with us, connect with us on the MGS LinkedIn page.
• To see precious metal melting and refinement in action, visit the MGS YouTube
channel.