GOLD AND SILVER Flashcards
The unit used in weighing gold is the ______
troy ounce (1 troy ounce = 31.1g)
The naturally occurring gold-silver alloy is called
Electrum
Green gold used in jewelry contains
copper and silver
White gold contains
zinc and nickel
Gold’s purity is often assessed in _____, with _____ gold representing pure gold
Karats; 24-Karat
It is harder than gold but softer than copper.
Silver
Silver ranks about ____ among elements in terms of natural abundance in the earth’s crust.
66th
_____ for tableware and other solid-silver objects is 92.5 percent silver and 7.5 percent copper.
Sterling silver
are used in medicine as antiseptics
and bactericides
Colloidal silver
a silver-protein compound, is a local antiseptic for the eyes, ears, nose, and throat
Argyrol
Are used in emulsions for photographic plates, film, and paper.
Silver-halide salts (bromide, chloride, iodide)
The arrival of the ________ by the end of the ________saw the
beginning of systematic exploration work and the introduction of modern methods
of mining and ore dressing.
Americans; 19th century
By 1938, the ______ had already produced a total of
PHP189,000,000 worth of gold, a figure equivalent to 2,700,000 ounces of gold
Baguio District
The gold mines in operation in the Baguio District were
Benguet Consolidated, Itogon, Balatoc, Antamok Goldfields, Baguio Gold, Benguet Exploration, Big Wedge, Demonstration and Cal Horr.
Estimates of gold ore reserves in the Philippines, as of 1996 amounted to ___________ with a weighted average grade ranging from 0.05 – 20.00 % g Au /
MT.
162.8 million metric tons
Two major magmatic arcs, the ___________ and _________,
are the most prolific gold producers in the country
Western Luzon and Eastern Philippine arcs
The recognized gold province and gold districts include:
- Gold province is the Eastern Mindanao Gold Province (three gold districts, namely, Surigao Gold District, Central Gold District, and
Masara Gold District) - Gold districts are
(1) Baguio-Mankayan Gold district ; (2) Camarines Norte Gold District; and
(3) Masbate Gold district.
one of the oldest and richest gold mining areas in the country, producing well in excess of 800 tons of gold, more than any other
gold-field in the Asia-western Pacific region
Baguio-Mankayan Gold District
One of the most dense in terms of number of reported deposits and prospects per unit area.
Camarines Norte Gold District
Is the site of the world class Aroroy gold deposit, which accounted for 12% of pre-World War II (1939-40) gold production in the
Philippines
Masbate Gold District
Philippine gold deposits may be genetically divided into two groups,
namely:
Primary-hypogene Au-Ag deposits, and Secondary-supergene
deposits.
Primary-hypogene gold-silver deposits include various genetic subtypes such as:
Epithermal/ mesothermal, skarn or contact metasomatic, and copper by products
Secondary-supergene deposits include
Placer gold and gossanous gold
deposits
Are epigenetic bodies formed at
temperatures ranging from 180° - 300° C and are predominantly hosted by volcanics, plutonics, wackes and volcaniclastics which are generally of andesitic
to dacitic composition.
Epithermal gold deposits
Economic contact metasomatic deposits that have already been developed are
Thanksgiving Mine (Benguet Exploration Inc.) and Siana Mine (Surigao Consolidated)
Export markets for gold are mainly
Japan, South Korea and United Kingdom.
For silver, the country’s major markets are
Japan, United Kingdom, China and Korea
______, _________, and______ methods
are employed to recover gold from run-of-mine ore.
Carbon-in-pulp (CIP), Carbon-in-pulp (CIP), and Heap leaching
The CIP/CIL method lowers capital cost by almost __ as it eliminates the use of filtration and
decantation units.
50%
