I Try To Identify A Variation Of A Common Stamp, The Victoria 1/2 Pence

The ordinary one is green...


Thank you for help

Nicolas

The ordinary one is blue-green. The (yellow) zinc-chromate used for the ink was soluble in water. Dampness and soaking cause the stamp to turn blue. It is a 'water-damaged' stamp,

Thank you :-)

It's also possible that stamp changed it's color, from sunlight. Other philatelists have showed such stamps here,but they were from different place of origin, if remember correctly it was a case of color change at US stamps. I will search for the topic again and if I find it I will post a link to it to see.

@post_pe,

The blue stamp was listed in the SG catalogue. The listing was deleted after it was shown the zink chromate was due to the change in the colour from blue-green to blue.

There is a note in the Stanley Gibbons catalogues that explains this. The specialised catalogue explains this led to delisting the stamp.

The colour being bright blue and not faded blue is a very strong clue that it is this change in the colour caused by soaking.

NSK,
Thank you for pointing me this information. I didn't know this.
I apologize ,for misleading the OP.

Don't worry.