Mineralogy

Ammolite

ammolite

Ammonite is an iridescent gem formed within an ancient marine fossil for which it was named—ammonite. Originally discovered by the Blackfoot Indians, ammolite is mined only in Southern Alberta, Canada. Most ammolite is assembled into doublets or triplets to increase durability because solid ammolite is usually thin and fragile, If it’s untreated and solid, ammolite is usually priced per carat and shaped as a freeform to maximize weight.  Extra fine quality ammolites display three or more sharp, brilliant colors with no 

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By | 2017-03-19T08:36:30+00:00 February 25th, 2017|Categories: Geology, Mineralogy|Comments Off on Ammolite

Mineral Identification by Spectroscopy

FIG. 35 gives an idea of the spectroscope and of its different parts. P is a flint glass prism, having a refracting angle of 60° and resting on a brass plate fixed on a brass support, S. The brass plate carries the collimator tube C, in the end of which nearest to the prism is fixed a lens, the other end being closed by a plate in which there is a vertical slit, which can be widened or narrowed as required by means of a small screw

The tube E has also on the end nearest the prism a lens, and at the other end a reduced photographic millimetre scale which can be seen through the telescope T

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By | 2017-03-19T09:19:19+00:00 January 11th, 2017|Categories: Laboratory Procedures, Mineralogy|Tags: |Comments Off on Mineral Identification by Spectroscopy

Properties of Gold & Alloys

From very early times the ancients were attracted by the beautiful colour, the brilliant lustre, and the indestructibility of gold, and spared no pains in the endeavour to acquire it. In the code of Menes, who reigned in Egypt in 3600 B.C. or about 2000 years before Moses, the ratio of value between gold and silver is mentioned, one part of gold being declared equal in value to two and a half parts of silver, and it is, therefore, clear that the extraction of both metals from the deposits containing them must have been carried on before that time. It is, indeed, probable that gold was the first

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By | 2017-03-17T19:07:04+00:00 January 11th, 2017|Categories: Mineralogy|Comments Off on Properties of Gold & Alloys

Crystallisation of Gold

Gold crystallises in the cubic system, occurring frequently in nature in the form of cubes, octahedra and rhombic dodecahedra. Cleavage is never exhibited. Single detached crystals are comparatively rare, and the crystals are usually attached end to end, forming strings, and branching, arborescent, or moss-like masses, which are composed of microscopic crystals, usually octahedra. These forms occur frequently in quartz veins, but the single crystals, which are usually of larger size—viz., from ¼ to 1½ inches in diameter — are mainly found in drift deposits. They are rarely perfect or

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By | 2017-03-17T19:07:05+00:00 January 11th, 2017|Categories: Mineralogy|Comments Off on Crystallisation of Gold

Descriptive Mineralogy Classification

Scope of Descriptive Mineralogy. — It is the province of Descriptive Mineralogy to describe each mineral species, as regards: (1) form and structure; (2) physical characters; (3) chemical composition including blowpipe and chemical tests; (4) occurrence in nature with reference to geographical distribution and association with other species; also in connection with the above to show how it may be distinguished from other species. Further, it should classify mineral species into more or less comprehensive groups according to those characters regarded as most essential. Other

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By | 2017-03-17T19:08:10+00:00 December 22nd, 2016|Categories: Mineralogy|Comments Off on Descriptive Mineralogy Classification

Crystal Structure of Solid Solutions using X-ray Spectrometer

“It would seem as if the methods used to date for the elucidation of this complex problem have yielded all they are capable of yielding and that further straining of these methods will only serve to confuse the issue, the point having been reached when this juggling, no matter how skilfully done, with allotropy, solid solutions, and strains is causing weariness without advancing the solution of the problem. The tendency of late has been to abandon the safer road of experimental facts and to enter the maze of excessive speculations, in which there is great danger of some becoming hopelessly

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By | 2017-03-17T19:08:12+00:00 December 22nd, 2016|Categories: Mineralogy, Various|Comments Off on Crystal Structure of Solid Solutions using X-ray Spectrometer

Mineralogy & Flotation: Floatability VS Selectivity Test Assessment

flotation_1Mineralogy is the driving force behind flotation performance. A flotation batch and rate test measures this as mass pull recovery and concentrate grade. The real data from a rate test can be processed to determine the flotation kinetics of metal, mineral and gangue. flotation_rate_determination_testWhat we cover here is what are kinetics and what do they mean. Special attention is paid to the definition of floatable gangue. How flotation kinetics are used to understand and optimized flotation performance is covered in the next series. Two other articles describe how a rate test is conducted and what

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By | 2017-03-17T19:12:29+00:00 November 22nd, 2016|Categories: Flotation, Mineralogy, Tools of a Metallurgist|Comments Off on Mineralogy & Flotation: Floatability VS Selectivity Test Assessment

Flotation Kinetics: Mass & Water Recovery VS Entrainment & Mineralogy

flotation_1

This covers the recovery of entrained solids with water and the relationship between mineralogy and flotation performance; both are described in terms of flotation kinetics. The starting points for the relationship between mass and water recovery other products of a flotation rate test. flotation_entrainmentIn addition to concentrate mass, metal or mineral and floatable gangue. If the mass of water in each concentrate has been measured, then a fourth set of kinetics can be added which defines water recovery. This is useful if dealing

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By | 2017-03-17T19:12:32+00:00 November 21st, 2016|Categories: Flotation, Mineralogy, Tools of a Metallurgist|Tags: |Comments Off on Flotation Kinetics: Mass & Water Recovery VS Entrainment & Mineralogy

Gold Chloride

Gold Monochloride or Aurous Gold Chloride “AuCl” is a salt is prepared by heating the trichloride to 185° in air for twelve hours. It is non-volatile and unaltered at ordinary temperatures and pressure by dry air, even when exposed to light, but begins to decompose at temperatures above 160°, and the decomposition is complete if it is heated at 175° to 180° for six days, or at 250° for one hour. Its density is 7.4. Water converts aurous chloride into a mixture of gold and gold trichloride. It is a citron-yellow amorphous powder.

Auro Aurichloride

Au2Cl4 is a dark red compound

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By | 2017-03-17T19:16:23+00:00 October 24th, 2016|Categories: Gold Extraction, Laboratory Procedures, Mineralogy, Reagents and Chemicals|Tags: |Comments Off on Gold Chloride

Gold and Silver Alloys

gold-and-silver-alloysGold and silver unite in all proportions, yielding alloys which are harder, more fusible, and more elastic than either metal. The hardest is that containing two parts of gold to one of silver. The colour of gold is sensibly lowered by the addition of very small quantities of silver, and on increasing the proportion of the latter, the colour changes by tints of a greenish-yellow (when from 20 to 40 per cent, of silver is present) to white, with a scarcely perceptible yellow tinge (when 50 per cent, of silver is present), and silver-white (when more than 60 per cent, of silver is present)

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By | 2017-03-18T11:08:13+00:00 October 24th, 2016|Categories: Gold Extraction, Mineralogy|Comments Off on Gold and Silver Alloys