Of the circular British Guiana stamps of 1850-51 it is hardly fair to speak, as they were issued and became obsolete before even the oldest philatelist ever thought of collecting; but if any far-seeing individual had then invested the modest sum of thirteenpence in the purchase of an unused copy of each of the four values, and had had them "laid down" until the present year of grace, or even until so comparatively far back as 1890, the sum they would realise in open market would not fall far short of £2,500. So, too, with the very rare large oblong type-set stamps of 1856, one of which--the One Cent, black on magenta--is literally unique.
The smaller stamps of 1862, printed from ordinary type with a frame of fancy ornaments, and issued on a shortage of One, Two, and Four Cents stamps, were for some considerable time fairly common, being obtainable for a few shillings, or sometimes, if one were fortunate, for pence; now a used set of the commonest variety of each value costs nearly £30.
Canada provides a rarity, dating back to 1851. A stamp--and it is a beautiful piece of work--of the apparently peculiar value of Twelve Pence was issued, but for some reason a very small portion of the large supply was sold, the remainder disappearing without a trace, never to be found even to this day: that stamp is now worth two thousand times its original cost. The reason for the value being expressed somewhat quaintly was that, whereas "One Shilling" was a fluctuating amount according to locality, "Twelve Pence" was the same everywhere.
It goes without saying that it is the rarities which have appreciated the most, and therefore a list of the stamps which ought to have been secured as an investment is practically a list of the rare and scarce stamps.
Beautifully engraved, of chaste design, and of quaint shape, the Cape "triangulars" are, and always have been, favourites; but they have been out-distanced, as regards profitable investment records, by the two roughly-executed stamps, of similar design and shape, printed from hurriedly made stereotyped blocks to meet a temporary shortness of the ordinary One Penny and Fourpence.
These provisionals, erroneously called (as they always will be) "wood-blocks," were issued early in 1861, and the ordinary specimens are of considerable scarcity even used, and very difficult of acquisition unpostmarked; much more then are the errors, caused by the unintentional inclusion in the group of stereotypes of each value of one block of the other denomination.