The Neals list this salt as the SD-2. It is made in the following colors. Clear in which it is Scarce,Opalescent which is very rare, Opalescent light blue listed as extremely rare, and Cobalt blue which is listed as very rare. The Boston and Sandwich Glass Company manufactured this mold.The base on this variant is a waffle diamond pattern with nine small dots in each diamond.
The Sd-2A is listed as very rare by the Neals. It is only offered in clear Flint glass. The only difference between the SD-2 and the SD-2A are the Diamond Waffle designs on each of the base's. On this salt the Diamonds only have 4 larger dots instead of 9.
SD 4,A,B,C,D,E Series
Over all this is a rare mold in all of the variants. The difference being the very top of each salt (Scallop type) and the bases which have differing center diamond waffle designs and one with an elongated 8 point star. The first SD-4 series salt in my collection is the SD-4A . This salt is listed as rare and was only charted in Cobalt Blue. My Salt is clear and is not listed with this base in any of the other variants. At a minimum this is a rare salt and could possibly be extremely rare.
This is the Neal listed SD-4D. It was only available in Clear Flint glass and is listed as scarce. It was manufactured at the Boston and Sandwich Glass Company. The Top scallops are the same shape on the SD-4,SD-4A,SD-4B , SD4-C and this one in my collection the SD-4D. The difference on this one is the elongated 8 point star design in the center of the base.
I have two of these SD-4E salts in my collection. I got very lucky at a Jefferey Evans auction in 2012. The difference in this salt from the rest of the SD-4 series is that it is (Taller) but has less of scallops and the Diamond waffle design on the base is also different The Neals list this salt as extremely rare. This variant was only made in Clear Flint glass at the Boston and Sandwich Glass Company .
This is my other SD-4E salt
The SD-5, 5A, 6, 7, 7A, 8, 9, 10, 11 and 12 Series. SD- 7
The SD-7 was manufactured in a lot of different colors. In Clear it was plentiful. In Pink it was rare.In Medium Amber and dull amber it was listed as rare.In red amber it was listed as very rare. In Light green it was scarce. In yellow green it was rare. Lastly in light blue,medium blue and cobalt blue it was listed as scarce.
The scallops are the same as the SD-7 however the difference in the two molds lie in the base design. On the SD-7A the base has a very defined 16 point long rayed sun burst where as the SD-7 has a 16 point sun ray design but the individual rays are stubby (Shorter) in length.
This could be quite rare salt this one looks exactly like the SD-7 and the SD-7A however it clearly has a completely different sun burst base. On this salt which is not listed in Neals Charting the individual rays ( 16 of them) are thinner and spaced more proportionally.This could be an extremely rare example. More research is needed.
The SD-11 is different in the top rim border then the rest of the series in that it has tall rounded scallops with small points between them and in the flat cornice area there are 8 round jewells between two chain links at the pillar tops in the corners. The base has a thicker 12 rayed sun burst. This salt was manufactured in the following colors. Clear in which it is plentiful, Opalescent which is rare, blue opalescent which is very rare and blue tinted which is listed as Scarce. The clear salt shown below here in my collection is listed as plentiful. This salt dish was manufactured at the Boston and Sandwich Glass Company .