Previous Study of the Jigdalak Area:

The Jigdalak ruby mine has been known to the local people since ancient times. Historical evidence indicates that the Jigdalak ruby mine in Surobi district was utilized as far back as 700 years ago. For instance, in the year 1200 AD, Mohammaduddin, a gem trader, sold beautiful ruby crystals to Kublai Khan and other notable historical figures. At that time, traders could not distinguish between rubies and spinels. Over the past hundred years, this mine has been studied by various geologists, including Gresbach, Badoni, Berlow, Hayden, Epler, Abdullah Khan, Drab, Chersky, and others. Unfortunately, very little published or unpublished material from these geologists has reached us.

In 1907, the Indian geologist Hayden conducted explorations for alluvial deposits in the Jigdalak area but did not find any rubies. The primary mine of this region was compared by Hayden and later by Epler (in 1933) to the famous Mogok ruby mine in Burma. However, the quantity of rubies in Jigdalak was found to be much lower than in Burma. These geologists concluded that Jigdalak is unsuitable for large-scale gemstone mining but recommended extracting marble while also extracting rubies and spinels concurrently. Regarding the type of deposits, both experts suggested continuing work in the area. In 1942, over two months, Chersky conducted survey and exploration work to identify the primary and secondary deposits in the valleys of the Solnav and Gurmangi rivers. In these alluvial deposits, between 10 to 15 trenches were dug, with 24.9 cubic meters of rock samples collected.

The alluvial deposits were examined using shafts, from which 58.7 cubic meters of rock samples were taken. After washing all these materials, 83.6 cubic meters of concentrates were obtained, primarily composed of red and pink garnets, with occasional ruby and spinel crystals that were deemed to have no practical value. In the main mining site, samples from areas like Kan Kalan, Lal Puri, and Khalwat were also collected, totaling 25.6 cubic meters. From these samples, a few pink spinel crystals (one crystal was approximately 3/4 of a carat) and small ruby crystals were obtained. Additionally, in the Khalwat area, an amethyst crystal was found with a length of about 10 centimeters. Based on his findings, Chersky also evaluated the Jigdalak mine negatively, like his predecessors, and suggested the region be used for marble extraction.

In 1966, Afghan geologist Dr. Sohbat studied the area and reached the same conclusions as the earlier specialists. According to his findings, rubies in the marble layers did not have significant economic value as gemstones but could be used as polishing material. Between November 1973 and 1974, Soviet specialists (G. A. Orlov, A. V. Zdan, P. S. Matov, G. S. Hublov) conducted an exploratory study of a 15.5 square kilometer area at a 1:10,000 scale. In the more promising areas of Jigdalak, Kan Kalan, and Khalwat, three trenches (303 cubic meters in total) were dug, from which three bulk alluvial samples (totaling 34 cubic meters) were collected. As a result of these surveys, a schematic map of the Jigdalak mine was created, preliminarily marking the locations of ruby mineralization in the Noristan series marbles (AR-PR). The map also defined large-scale vertical mineralization of rubies (over 400 meters), which was found unevenly distributed among the rocks.

Only small mineralization lenses and nests of rubies were identified, linked by narrow bands that formed through the dolomitization of large marble masses during hydrothermal changes. These zones are saturated with minerals like phlogopite, spinel, and clay-like sericitized materials. Bulk samples were collected from the base of the trenches, which were dug by locals along ruby-bearing dolomitic marble zones. The bulk sample volume from the Jigdalak site was 8 cubic meters, yielding ruby concentrates of 977.5 grams and 1,069.1 grams, respectively. After cleaning and refining, the crystalline ruby material was categorized into three classes:

• First Class: The crystals are transparent or semi-transparent, with no visible cracks. They range in size from 5 to 20 mm, sometimes larger, and have a deep red (cherry) color. The total weight of these crystals is 408 grams, with some rubies weighing up to 6 grams.
• Second Class: The crystals are irregularly shaped, sometimes transparent and sometimes opaque, with visible cracks. Their size reaches up to 5 mm, and the total weight is 1,767.5 grams.
• Third Class: The lowest quality crystals, with a total weight of 2,069.6 grams.

For further analysis of the crystalline material, the bulk of the concentrate (4,875 grams) was sent to the former Soviet Union, of which 4,800 grams were analyzed. According to B. M. Dvakov, the 4,800 grams of crystalline material had no gem value, as they contained no economically viable ruby or spinel crystals. Moreover, the remaining 4,875 grams of rubies were found to have limited value and their origin could not be clearly determined.

Given the widespread horizontal and vertical distribution of ruby mineralization and the presence of excavations by locals aimed at extracting rubies, G. A. Orlov and others concluded that the Jigdalak mine still has significant potential. They recommended further exploratory work to assess its feasibility for extraction.