Hi - welcome to the GMB. In this instance your picture, although smaller than the size required usually for id here, shows what appears to be a piece of Primrose (yellow) Pearline, which had its origins (in the U.K.) with a company by the name of George Davidson, in Gateshead. There is a similar product in blue for which I think cobalt was responsible for the colour. Ingredients include phosphates and arsenic, which contribute to the opaque parts of the article when the piece is re-heated - the longer the re-striking the greater extent of the opaqueness.
Pieces from George Davidson were often marked with a Registration No., inside the piece is often favourite. I could be wrong, but have a feeling that Davidson Registered a smaller number of their designs than some of the other pressed glass factories.
Assuming your piece is period than it might date to the 1890s - Davidson's patent is dated 1889 - but I always worry that these things have been recreated in the C20 - so not entirely sure ........... this may well have been intended as a posy vase - the Victorians were very keen on such things. For obvious reasons people here are very keen on knowing dimensions - saying simply this is small is a reasonable comment, but accuracy is preferable.
Sorry - regret no one here is going to discuss values with you - too variable - take dozen people and they'll almost certainly give you a dozen different figures. Look for similar items at on line auctions sites, and you should get some general indication of value.
Regret this doesn't provide much specific information on your piece - let's hope someone recognizes the pattern/design.

P.S. meant to say ............ If you shine a black light or u.v. torch on this one it will glow.