Large cushion shape Pink Spinel from Tajikistan
A gem dealer sent us this piece of rough pink Spinel which is from Tajikistan. Tajikistan borders Afghanistan on their northern border and this new source of Spinel is from one of the most remote places in the world. Due to the current war and other dangers in that region, it was an adventure for the dealer to acquire such high quality material.
After cutting 2 pink Spinels for him, he sent us this extra large piece with instructions to cut it for both brilliance and maximum weight retention. Below are photos and a description of the step by step process of cutting this world class gemstone.
Below you will see step by step how I faceted the Spinel
Step 1 - Marking the Rough
This is the piece of pink Spinel rough which I started with.
I used a black Sharpie to draw a line indicating appx. where the keel line of the pavilion would be.
Step 2
I sawed the rough gem material in a manner which would produce one large gem and one smaller gem. Both stones lent themselves to be cushion shapes.
Step 3
After shaping the large piece, I epoxied it to a dop stick which holds it during the cutting process.
I will be cutting the pavilion first.
You can see a black line which indicates a small crack in the side of the stone. This will be cut away during the cutting process.
You can also see a light colored, arrow shaped, area near the top, which is a crack. This crack will also be cut away during the cutting and shaping process during faceting.
Step 4
Here you can see the first few facets have been placed onto the stone giving the gem its basic shape.
The cutting is done on a fine grained diamond lap.
Step 5
More facets get added in the process of developing a 'pattern'.
Step 6
Here you can see that the pattern has gotten more complex.
Although there area many standard patterns uses in faceting, when cutting an important stone such as this one, it is sometimes necessary to invent a pattern of facets which can better accomplish the desired objective, which is what I did when cutting this gem.
Step 7
You can now see that many of the facets have been polished. At this stage, smaller facets can be added for more detail and other fine tuning is done to make the facets meet perfectly.
Step 8
After the pavilion is finished, the gem is turned over and work is done on the top, or 'crown', of the gem. Again, the first steps are performed with a fine grained diamond lap.
Step 9
You can now see that most of the facets have been polished on the crown.
Finished 26.60 carat Spinel
After final polishing of the crown and also the girdle (outer edge), the gem is removed from the dop stick.
I am very pleased with the results. The color is a deep rich raspberry pink.
The final weight is 26.60 carats, which is 53% of the weight of the preform. It is unusual to retain so much weight. This was accomplished with a deep pavilion and modifications to the shape.
Fine pink Spinels over 10 carats are rare. The value of this gem is probably close to $90,000.
Denton Anderson,
Gemologist & Gem Cutter
click photo for Video
Graduate Gemologist, GIA, GG
Over 20 years of experience.
