I read an interesting book Holy Vedas and Islam by Q.S.Khan.
To me the whole thing seems to be labored and possibly an attempt at subtle conversion attempt to woo Hindus.
Blackstone in Kaaba.
In the 10th century, an observer described it as being one cubit (slightly over 1.5 feet (0.46 m)) long. By the early 17th century, it was recorded as measuring 1.5 yards (1.4 m) by 1.33 yards (1.22 m). According to Ali Bey in the 18th century, it was 42 inches (110 cm) high, and Muhammad Ali Pasha reported it as being 2.5 feet (0.76 m) long by 1.5 feet (0.46 m) wide.
The Black Stone was first described in Western literature in the 19th and early 20th centuries by European travellers in Arabia, who visitedthe Kaaba in the guise of pilgrims. Swiss traveler Johann Ludwig Burckhardt visited Mecca in 1814, and provided a detailed description in his 1829 book Travels in Arabia:
It is an irregular oval, about seven inches in diameter, with an undulated surface, composed of about a dozen smaller stones of different sizes and shapes, well joined together with a small quantity of cement, and perfectly well smoothed; it looks as if the whole had been broken into as many pieces by a violent blow, and then united again. It is very difficult to determine accurately the quality of this stone which has been worn to its present surface by the millions of touches and kisses it has received. It appeared to me like a lava, containing several small extraneous particles of a whitish and of a yellow substance. Its colour is now a deep reddish brown approaching to black. It is surrounded on all sides by a border composed of a substance which I took to be a close cement of pitch and gravel of a similar, but not quite the same, brownish colour. This border serves to support its detached pieces; it is two or three inches in breadth, and rises a little above the surface of the stone. Both the border and the stone itself are encircled by a silver band, broader below than above, and on the two sides, with a considerable swelling below, as if a part of the stone were hidden under it. The lower part of the border is studded with silver nails.
Visiting the Kaaba in 1853, Richard Francis Burton noted that:
The colour appeared to me black and metallic, and the centre of the stone was sunk about two inches below the metallic circle. Round the sides was a reddish brown cement, almost level with the metal, and sloping down to the middle of the stone. The band is now a massive arch of gold or silver gilt. I found the aperture in which the stone is, one span and three fingers broad.