Inclusions in ruby. Using the example of a Vietnamese natural ruby (short presentation)

1.

Inclusions in ruby. Using the
example of a Vietnamese
natural ruby (short
presentation)

2.

Photo 1

3.

Visual purity of ruby
Photo 2

4.

Photo 3 Panorama of inclusions (magnification x200). Rutile cotton
inclusions in ruby, clouds of rutile particles

5.

Photo 4
Dense milky clouds
consisting of the smallest exsolution
particles of rutile.
According to the GIA methodology
, dense milk clouds are
a diagnostic sign of Vietnamese rubies
(fragment of the original photo 3,
at this magnification, it is impossible
to confuse a haze of the smallest solid
particles with a cloud of gas bubbles)

6.

Photo 5
Inclusions of short
rutile needles,
including in the form
of arrowheads

7.

Photo 6
Panorama of some
corroded solid
(mineral)
inclusions in ruby.
Some fragments of
the mineral hematite
are limonitized and
have yellow-brown
films of hydrated iron
oxide

8.

Hematite minerals (ore fragments) are gray in color with a metallic luster and bluish
streak in the form of irregular lamellar grains with an uneven, stepped or shell fracture.
The protogenetic nature of inclusions in ruby is indicated by the corrosion (dissolution of
the surface) of the minerals of the inclusion. The undissolved minute particles of iron
oxide around the minerals indicate the absence of temperature treatment
Photo 7
Photo 8
Photo 9

9.

Photo 10
The protogenetic nature of the solid
inclusion in the ruby is indicated by the
presence of tension cracks around it
(tension halo), which are visible at
certain positions of the stone and angles
of incidence of light. Examination and
shooting in polarized light made it
possible to see inclusions hidden in
opaque cavities of ruby (for example, in
photo 3)

10.

Photo 11
Photo 12
Primary two-phase fluid inclusion in ruby
(fluid and blue gas bubbles that are not
transparent in the transmitted light) with
decrepitation halos surrounding them.
Inclusions indicate both the natural origin of
the ruby and the absence of its heat
treatment

11.

Photo 13
Photo 14
Primary three-phase
fluid inclusion in ruby
with the presence of
mineral phase.
The walls of the cavity are stained
with the presence of iron oxide.
Inclusions indicate both the natural
origin of the ruby and the absence of
its heat treatment

12.

Photo 15
Photo 16

13.

Comment on photo 15,16:
The lines (stripes) visible in the photographs are on the surface of the ruby (the results of
manual cutting and polishing), in no way can they be mistaken for ruby growth lines.
Some of the lines are a continuation of the well-visible chips on the ribs. The stripes do
not cross faceted borders, the distances between them are different, the stripes themselves
are of different thickness, do not contrast and are not concentric.
Photo 15 with x100 magnification, photo 16 is a fragment of photo 15 enlarged in a
computer.

14.

The dimensions of the stone (approximately): length and width 10x9 mm, thickness 5
mm, based on linear dimensions, taking into account the features of the cut, its weight is
about 5 carats. There are no inclusions (turbidity) visible to the naked eye, the stone is
visually completely clean, homogeneous and transparent. The color of the stone is red of
medium saturation with a slight purple tint.
All inclusions are concentrated in one area of the stone with a diameter within one
millimeter. The presence of these inclusions indicates both the natural origin of the ruby
and the absence of its heat treatment.
The detected inclusions correspond to inclusions characteristic of Vietnamese rubies:
(https://www.gia.edu/gems-gemology/winter-2019-ruby-geographic-origindetermination ).
Vietnamese rubies are found in the mineralized marble belt, which is almost identical to
the geological conditions in which rubies are found in the Mohawk region of Myanmar,
according to the GIA conclusion, high-quality Vietnamese rubies are no worse than
similar rubies from Myanmar.
Author — Sergey Korshunov: [email protected], presentation in Russian:
https://ppt-online.org/1557931