Topic: Early Mdina cobalt blue sidestripe button rim

[flying free]

as it says, I believe it's from the cobalt pot dated 1968-1969 i.e. the first year of production and made by Michael Harris.
The interior is full of chloride streaks much like an inside out vase.  The exterior is very dark cobalt blue like this almost inside out vase here.
http://www.glassmessages.com/index.php/topic,42684.msg237719.html#msg237719
There are escaped silver chloride streaks in the sidestripes which makes them look slightly green.
 The rim is a wonky button rim. It's fairly flat not bulbous when looking side on, on the narrow side.
The curious thing about it is there is a very neat, deliberate 'bridge' made in it, that shows as two circular marks, one on each side on the outside in the middle, and the bridge can be seen peering through to the inside. 
My pictures have been well lit to show the colours.  It is most definitely cobalt blue
m

[flying free]

more pics
the last one I had to shine the light directly into the vase to get the colours to show.  The camera makes it look purply but it's definitely cobalt with chlorides on the inside
m

[glassobsessed]

The purply tone is what I have had trouble capturing on camera, especially with electric light. That is what I think of as the cobalt blue, I think the blue in my two facet cut IOs and tricorn bottle is different but which was the cobalt?

I just tried to get a photo to show the difference colours together accurately and failed, will have to wait until daylight and a little sunshine tomorrow.

BTW, absolutely exquisite sidestripe m.

[flying free]

thanks 
I'm just trying to find a good photo of it compared to the  colour of the fish.  Again I found it very hard to get the camera to recognise the different blue tones to show it clearly.
The best comparison is with the overlay blue and white vase, where both are the same deep intense cobalt blue. 
I'll look some pics out and post with the fish in a sec.
m

[flying free]

here's one with the fish - it's the best I could do
and another with my cobalt and white vase to show the match in colour

[Nemmie]

Very nice indeed, I have one with a similar rim but no bridge.

http://www.glassmessages.com/index.php/topic,48366.msg272724.html#msg272724

[chopin-liszt]

Fabby, M - I'm all different shades of violent green - also impossible to capture on camera.
I would hinestly think the bridge is just an artifact, not deliberate.

Given there was only one pot of cobalt melted, is it possible that some of it was "diluted" with clear glass?
It is still speculation that it was '68 ish it was melted, because my "precious baby fish" was dated to '68 by Tim and Elizabeth and that contains swirls of cobalt.

The casing on my "new" bottle is much like the colour you have here. What appears to be diluted cobalt.

[flying free]

Thanks Nemmie
and Sue, thank you and glad you like it
It's possible the bridge was where the sides 'stuck' together inside but it is also possible I suppose, that it was 'poked' to make the bridge.
 
Looking carefully at it, it looks as though the interior was clear ( I can tell as the 'bridge' link is clear with chlorides in it), then  with the chlorides put on which surround the internal blob in swirls as though it was whirled around to swirl the chlories, then the whole was cased in the thick cobalt blue and then the clear side stripes put on - the side stripes have some chlorides in them as well which makes them have a very pale greeny yellowy tinge.

The cobalt colour isn't diluted at all  as the vase is ink midnight blue without any light through it.
I purposefully took the photos with strong lighting to show the colours inside the vase but
the outside is very deep dark cobalt blue.  I've popped it on a shelf at the moment and with light on the front of it but none through it, it looks nearly black.
Sorry to ramble on, I've just realised did you mean yours looks like diluted cobalt used for the casing?

re the date of the cobalt, was it speculation in M Hill's book then about it being used in the first year of production?
he is very clear in saying cobalt and amethyst in their unmodified form were only used as final colours in for a short period of time in the first year of production. 
I would say that the cobalt on my vase is in unmodified form ... i.e. it hasn't been mixed/modified by adding anything else to the cobalt, but was used as plain cobalt to case a 'clear coated with silver chlorides' interior. 
I can understand that it could also be describing a piece such as John's cobalt fish which has no other colour in it all other than one under layer of cobalt and then cased over with the wings made of another layer of cobalt.


The alternative to 'unmodified' cobalt would be that the cobalt was mixed with something else to provide other colours perhaps?
m

[Lustrousstone]

The depth of colour will depend on how much colourant (cobalt aluminate or cobalt silicate or cobalt oxide) you use in the melt. Undoubtedly there was one pot of deep cobalt blue glass melted and possibly a pot or more with less cobalt but the other more common Mdina blue is not cobalt based. It is something that produces a hint of green in the blue. Even that is found in in varying shades.

What is also possible that apart from the one pot of blue, all the other stuff is based on clear glass and coloured using the concentrated colour discs on the pipe or very small melts of coloured glass applied to clear on the pipe. Colorants are the expensive bit.

To my eyes M's side stripe is coloured with cobalt, lots of it, as is her fish vase, but less of it.

[glassobsessed]

Ok my tuppeny worth re some of the blues. Starting with the Tricorn and Inside out vase in the first photo, that dull dark blue I would describe as more akin to indigo. In the second photo the vase and the fish are made with the light blue (sky?) like m's fish vase and have the decorative bits in what I think of as cobalt, the swirls on the vase and the wings on the fish. It has that almost purply tone that is quite diffeerent to the other blues.

Photos 3 and 4 are an attempt to contrsat the two dark blues next to each other.

To my eye these are not depths of the same tone, they are different tones.

M's sidestripe looks like cobalt unlike my inside outs, I don't think there is any of the cobalt in your fish though m.