This small spherical vase with short collared neck has a dark red glaze allowed to drip thickly at the base leaving the clay partially exposed. On one side is a circular decorative panel with a crackled ivory glaze and soft floral motifs in the same dark red colour. The vase is clearly stamped with the potter’s monogram, which looks like a reversed “R” sharing a stem with the letter “B”.
A large number of potters have the initials “RB”. All I can say with confidence is that this is not the signature I have recorded for Rick Ball, Robert Barron, Rolf Bartz, Robert Beck, Robin Best or Richard Brooks.
Monograms are often hard to read and I’m still not certain this says “RB”.
Postscript
A fellow collector has let me know that this is the mark of the South Australian potter Rhonda Boehm. She is briefly mentioned in Pottery in Australia, 25/4(1984): 60 as a member of the Potters’ Guild of SA, specialising in coloured clay slips and dry glazes over carved white clay. There is a picture of a stoneware vase in this style in Norris Ioannou’s Ceramics in South Australia 1836-1986, p. 287, incised ‘Boehm’. She also produced work under her maiden name Rhonda Longbottom, using an impressed ‘RL’ mark, with the R inside the L.
Australian Pottery 
I was delighted to find your blog after following a link from http://strangefragments.blogspot.com/
I completed the NSW TAFE ceramic certificate in the 1980’s and have a small collection of Australian pottery from that time (small because of my limited budget, but some pots just ‘spoke’ and I had to have them)I have just started to photograph my own pots that I’ve kept, but often wonder if any of the hundreds I sold at art shows etc. still survive – I’ll also photograph my small collection of Australian pottery because like you, I’m embarrassed to admit that some I have to stop and think hard about who made it.
The little pot in this post looks so familiar, but that iron brushwork was something we all aspired to.
…..looking forward to more of your posts