Tibet, 1890 AD., Glamda mint, Tangka, cf. KM C. 60.3.

Tibet, Glamda mint, dated cycle 15 year 24 (= 1890 AD.),
1 'Kong-par' Tangka (ø 26-26,5 mm / 4,64 g), ca. 0.800 silver, axes (as pictured) irregular alignment ↑→ (ca. 100°),
Obv.: , with Tibetan 15/24 in the centre, crescent and three dots above date arch within square, circles, dots and scrolled ornaments around.
Rev.: lotus pattern in a circle, surrounded by the eight lucky symbols. Order of the symbols clockwise from top: The magic umbrella [rin chen gdugs] at 12, Gold fish [gser nya] at 1-2, Holy lotus [pad ma] (the symbol had changed significantly to nine dots instead of a lotus) at 3, Diamond knot [dpal bevu] at 4-5, Gold wheel [vkhor lo] at 6, Satin cylinder [chos kyi rgyal mthsan] at 7-8, White snail of right spiral shell [dung dkar gyas vkhyil] at 9, Magic bottle [gter cher bum pa] at 10-11 o´clock, .
cf. KM C. 60.3 .

Year / Mintage
Cycle 13 Year 45 [AD 1791] / ?
Cycle 13 Year 46 [AD1792] / ? Reverse : a lotus in double circles, surrounded by the eight lucky symbols
Cycle 13 Year 46 [AD1792] / ? Reverse : a lotus in a single circle, surrounded by the eight lucky symbols
Cycle 13 Year 47 [AD1793] / ?
Cycle 13 Year 46 [AD1792] / ? design of the magic umbrella has been changed. This is the 3rd edition of 13-46 Tangka.
Cycle 13 Year 46 [AD1792] / ? new lotus pattern in a single circle, surrounded by the eight lucky symbols. The umbrella pattern is different from the above coin too. The fish pattern showing the two fish have formed a 'S' shape.
Cycle 13 Year 46 [AD1792] / ? The satin cylinder appeard of five dots.
Cycle 13 Year 46 [AD1792] / ? The satin cylinder appeared of six dots.
Cycle 15 Year 24 [AD1890] / ? the E symbol had changed significantly to nine dots instead of a lotus. Glamda Mint
Cycle 15 Year 24 [AD1890] / ? The lotus pattern is completely different from the above coin. This coin is rather crude design and the strokes are quite bold
Cycle 15 Year 25 [AD1891] / ? A 'S' shape is formed in the fish pattern. Glamda Mint
Numerous other varieties exist.

From http://ykleungn.tripod.com/tibcoin2.htm :

It is believed that Tibet had begun its own coinage probably in about 1760s. The first coin was minted by the order of Regent of the Tibet government Dican Hutuktu. As I know that the first Tibetan coin bears only the motifs of Buddhisim to assert its local origins, there is no any inscriptions on the both sides of the coin.

Some Western scholars believed that the first Tibetan mint opened in 1791, but operations were suspended two years later. In 1792, Qing government established a second mint in Lhasa to issue silver coins for the local market until 1836. But I have collected some speciments of Tibetan Tangka which denoted minting in 1791. Might be the dies had already prepared in 1791, but they were used two years later. Really, I am confused with the dating of the early Tibetan Tangkas. This can only prove that there were at least two mints existed in Tibet during the 1790's. The Tibetan silver coins normally were known as Tangkas, they were minted in Tibet during the period of 1791 to 1946. They exhibit a wide array of varieties and yet the features of Tibetan tangkas remained nearly invariable for over a century.

Two major types of Tangkas have been catalogued. The early minted Tangka coin features of a lotus in an inner circle, surrounded, in eight compartments, by the eight lucky symbols on one side, and on the other side, it features of an inner square with the date, surrounded by scrolled ornaments. I cannot determine the minting place of Kong-par Tangkas which denoted minting during the 1790's. Mr. Oliver D. Cresswell believed that they were probably minted in Giamda.
For the later minted Tangkas, it features on the reverse with a wheel symbol surrounded, in eight compartments, by the legend [Dgar Ldan Pho Rdang Co Las Nam Rgal] with means 'The gaden palace victorious on all sides'.

Normally Tangkas don't bear a denomination, and only the first six coins listed bear a date. They were minted between 1791 to 1891. They are known as "Kong-par Tangka" coins. For those bear without date are known as "Gaden Tangka".