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  2. Coin grading - Wikipedia

    en.wikipedia.org/wiki/Coin_grading

    Coin grading [1] is the process of determining the grade or condition of a coin, one of the key factors in determining its collectible value. A coin's grade is generally determined by six criteria: strike, preservation, luster, color, attractiveness, and occasionally the country/state in which it was minted.

  3. La Colosa mine - Wikipedia

    en.wikipedia.org/wiki/La_Colosa_mine

    La Colosa is a porphyry gold mine in Colombia. [1] The mine is located in Cajamarca, Tolima on the eastern flanks of the Central Ranges of the Colombian Andes.La Colosa has estimated inferred resources of 24,000,000 ounces (680 t) of gold, grading at 0.9 to 1.0 milligram per kilogram (1.4 × 10 −5 to 1.6 × 10 −5 oz/lb) of Au. [1]

  4. Grading systems by country - Wikipedia

    en.wikipedia.org/wiki/Grading_systems_by_country

    The Iranian grading system is similar to France's and other French-patterned grading systems such as Belgium, Lebanon, Venezuela, and Peru in secondary schools and universities. Since a grading guideline is not provided by the Iranian Ministry of Education, conversion to the international scales is carried out using conversion guideline ...

  5. List of primary education systems by country - Wikipedia

    en.wikipedia.org/wiki/List_of_primary_education...

    In India, the various bodies governing school education system are: The state government boards, in which the majority of Indian children are enrolled. The Central Board of Secondary Education (CBSE) board. The Council for the Indian School Certificate Examinations (CISCE) board. The National Institute of Open Schooling.

  6. Fineness - Wikipedia

    en.wikipedia.org/wiki/Fineness

    It is an extension of the older karat system of denoting the purity of gold by fractions of 24, such as "18 karat" for an alloy with 75% (18 parts per 24) pure gold by mass. The millesimal fineness is usually rounded to a three figure number, particularly where used as a hallmark , and the fineness may vary slightly from the traditional ...

  7. Academic grading in the United States - Wikipedia

    en.wikipedia.org/wiki/Academic_grading_in_the...

    Below is the grading system found to be most commonly used in United States public high schools, according to the 2009 High School Transcript Study. [2] This is the most used grading system; however, there are some schools that use an edited version of the college system, which means 89.5 or above becomes an A average, 79.5 becomes a B, and so on.

  8. Gold extraction - Wikipedia

    en.wikipedia.org/wiki/Gold_extraction

    Gold occurs principally as a native metal, i.e., gold itself.Sometimes it is alloyed to a greater or lesser extent with silver, which is called electrum.Native gold can occur as sizeable nuggets, as fine grains or flakes in alluvial deposits, or as grains or microscopic particles (known as colour) embedded in rock minerals.

  9. Mineral resource classification - Wikipedia

    en.wikipedia.org/wiki/Mineral_resource...

    There are several classification systems for the economic evaluation of mineral deposits worldwide. The most commonly used schemes base on the International Reporting Template, [1] developed by the CRIRSCO – Committee for Mineral Reserves International Reporting Standards, like the Australian Joint Ore Reserves Committee – JORC Code 2012, [2] the Pan-European Reserves & Resources Reporting ...