Ovruch slate spindle whorl - spindle whorl, carved out of pink and red slate stone (pyrophyllite slate), which was mined in the territory of present-day Ukraine, near the town of Ovruch in the 10th - 13th centuries. Ovruch masters diligently repeated the most successful form of a clay spindle whorl - biconical (the weight as if consisted of two truncated cones connected by broad bases) The spindle whorl weighed on average about 16 g, the height was from 4 to 12 mm, the outer diameter was from 10 to 25 mm, the diameter of the hole for the spindle was 6–10 mm. If the spindle whorl turned out to be too narrow, it was wrapped with a thread so that it would not slip during rotation. Slate - soft stone; on the samples found by archaeologists, there are still scuffs from the threads. The production of slate spindles in Ovruch was designed for wide sales. The merchants who bought the consignment of the spindle whorls made a considerable way with them, sold them in different lands. Ovruch spindle whorls are found by archaeologists not only in the territories of Kievan Rus, but in other regions. Production of spindle whorls was designed for a wide sale. According to A. V. Artsikhovsky, "they are exactly the same in Kiev and Vladimir, in Novgorod and Ryazan, even in Cherson, in the Crimea and in the Bulgaria on the Volga." The Ovruch spindle whorls were so valued that the owners carved their personal tags on them, and after the spread of writing - carved their names. In the 13th century, the stone spindle whorls become clay again: the Tatar-Mongol invaders destroyed Ovruch workshops.