Coal was very important to the Vietnamese economy so a stamp to commemorate the Cam Pha Coal Mine was issued in a 150D nominal and perforation 11.5. Here is the official stamp bulletin issued by the Vietnamese stamp agency that announces the publication of this stamp.
Here is the mint stamp
Mint block of four:
Here is a canceled to order stamp
Rare single franking of the 150D stamp used on a postcard on March 7th, 1960. The stamp had been devalued by 1,000:1 on March 1st, 1959 and was hence worth 15 new xu. The postage for postcards had just been reduced to 6xu on March 1st, 1960 but the sender or postal clerk was not aware of that fact.
Very rare multiple franking of the 150D stamp used on a surface letter from Hai-Phong to Rague, Czechoslovakia in March of 1959 paying the 300D surface letter rate in force at the time.
Interesting mixed currency franking featuring one of the Cam Phase stamps in 150 Old Dong, the 12 Year Republic 20Old Dong and two of the Tru’ng Sister stamps in 13 new xu. The old Dong was devalued by 1,000:1 so the two old stamps were only worth 17xu. So, there overall franking amounted 30xu which represented the surface letter rate to China.
Large envelope sent in June of 1960 by a member of the Czechoslovakian Embassy and by registered mail to Czechoslovakia. This letter is interesting in that it features a triple mix franking of official service stamps and general postage stamps in Old and New Dong. The collection of Old Dong stamps (August Revolution, Cam Phase Mine, Trade Exhibition, Peoples Sport, Union Congress and Democratic Women) amounted to a total of 3,650, the official World Union Congress stamps to 200D and as of March 1st, 1959 were worth only 3.85 New Dong. Together with the stamps in New Dong (Hong-Xuan Sluice, Radio Station Me Tri, 10 Years Peoples Republic of China, Women Day, Hung Vu’o’ng Temple and National Assembly) that amounted to 0.63xu the total postage came to 4.48 New Dong. Very unusual and rare combination.
Registration Nr. 100190