I think these are truly the only odd shaped stamps issued by India post so far. Ofcourse, I also consider any shape other than the regular rectangular shape as odd, like the diamond shaped, triangular shaped and round shaped. Though there are quite a few diamond and triangle shaped indian stamps issued over the years, these are the first and only hexagonal ones.
The two stamps were issued to commemorate the Alipore zoo's Aldabra giant tortoise called Adwaita. We all know about the folk tales of the tortoise who defeated the hare and won the race. Well, Adwaita was also a winner. Before it died in the year 2006 in Alipore Zoological Garden, Kolkata, Adwaita was perhaps the
longest living animal in the world having lived for more than 250 years.
This is a beautiful sheet with both the stamps placed alternately, almost every time against each other, in a symmetrical design. There are 5 of the Rs 15 stamps and 8 of the Rs 5 stamps making a total of 13 stamps in the sheetlet. The background is again a blow up of the tortoise.
There are three other formats of sheetlets that were issued, one with thirteen Rs 5 stamps, another with thirteen Rs 15 stamps and the third with five Rs 5 and eight Rs 15 stamps. I will in time get these other three too I'm sure.