Here is the very famous Crown of Monomakh, which is mentioned in the historical sketch and biography of this Russian Tsar.

Regards,
George.

Some notes relating to the period of the Crown of Monomakh:

The wholesale looting and destruction of property and life in Russia during the Mongol invasion of 1237-40 was a staggering blow which left the Russian people stunned, and for a time utterly disrupted the normal course of economic and political life. It is hard to estimate the Russian casualties but they must have been tremendous, and if we include the vast throngs of civilians, both men and women, who were enslaved by the Mongols they can hardly have been less than 10 per cent of the total population.

The cities suffered most in the debacle. Such old centers of Russian civilization as Kiev, Chernigov, Pereiaslav, Riazan, Suzdal, and the somewhat younger Vladimir-in-Suzdalia, as well as a number of other towns, were thoroughly destroyed, and the first three named above lost their former importance for several centuries. Only a few major cities in West and North Russia such as Smolensk, Novgorod, Pskov, and Galich (Halicz) escaped devastation at that time. The Mongol policy of conscripting master craftsmen and skilled artisans for the khan's service added a new burden even for those cities which had been spared physical destruction during the first period of the Mongol conquest.

The dispersion of Russian master craftsmen in the Mongol world all but exhausted, for a time, Russia's own reservoir of skilled man power. With the closing of the enamel shops of Kiev in 1240 and the murder or abduction of their artisans, the Russian art of making cloisonné enamel, which had reached such a high level in Kievan Russia, disappeared altogether. In the course of the 14th century some Limoges enamels were imported, and late in the century champleve enamels were made in Moscow; in the 16th century the Moscow craftsmen started producing cloisonné enamels, but these are rather coarse and bear no comparison to the Kievan types. The production of filigree works (skan') stopped for almost a century, after which it was resumed under the influence of Central Asian patterns. Specimens of Central Asian jewelry like Monomakh's Crown were brought to Moscow and some of the Russian master artisans who worked with jewelry in Saray (and possibly in Urgenj as well) succeeded in returning to Russia in the mid-14th century. When later on both Saray and Urgenj were destroyed by Timur, some of the craftsmen of the Khorezmian school who happened to survive the catastrophe might have been engaged by the grand duke of Moscow.

The niello technique too went out of use after the Mongol invasion and became popular again only in the 16th century. Nor is there evidence of production in Russia of glazed polychrome ceramics, including decorative tiles, in the late 13th and the 14th centuries.