After collecting quite a few MV bulbs, i had the thought: what’s the rarest mercury vapor bulb out there? I’ve heard things like clear SBMVs and MA/Vs are considered rare, but im wondering what would be considered the holy grail for any MV collector like myself.

This is a question with so many approaches towards it, so i will throw a few thoughts in.

Rarest combinations listed in a catalog would be something i saw in a sylvania catalog, A H34 Half coated low voltage 1000w lamp that had the /x phosphor coating and purple glass.

Rarest single one would be probably a one of the 3000w medium pressure lamps, or one of the 425w american lamps that ran at 265v.

Rarest of mine are a pair of Ken-Rad 100w mercury flood bulbs made sometime between 1959-1961. There is very little info and i got them from a lab for free in 2017.

Anyone else have any ideas, please kindly list them.

Yeah it's a fairly open ended question but there are certain wattages and phosphors that are rare.

Some rare phosphors include the /Y caution yellow lamps which were a yellow coloured mercury lamp intended for use at hazardous areas such as intersections, curves, and merges. Those were during the 1960s but weren't common and were delisted when HPS came out.

The /X deluxe white is also another rare phosphor. They were a purple stained lamp intended to boost red output that was rendered obsolete when the /DX phosphors were introduced.

As for wattages, the 425w lamp is pretty rare along with the 3000w medium pressure lamp. 700w lamps could be considered rare too, particularly in the less common phosphors.   

This is a question with so many approaches towards it, so i will throw a few thoughts in.

Rarest combinations listed in a catalog would be something i saw in a sylvania catalog, A H34 Half coated low voltage 1000w lamp that had the /x phosphor coating and purple glass.

Rarest single one would be probably a one of the 3000w medium pressure lamps, or one of the 425w american lamps that ran at 265v.

Rarest of mine are a pair of Ken-Rad 100w mercury flood bulbs made sometime between 1959-1961. There is very little info and i got them from a lab for free in 2017.

Anyone else have any ideas, please kindly list them.

First, Lets see if this reply to the above goes through and gets posted.
Starting off-topic...
About an hour ago there were some comments by Jamie (Morbid Angel) and when I went to reply to what he said, this site sent a message to me stating that the original message was off-topic or in so-many-words hands off to me. Sad that his messages evaporated. I was going to send him some good words of advice and wisdom, but blocking (to me) by the admins(s) stopped that dead in its tracks.  Pretty sad that that what you read here gets filtered like our newspapers. Anyways, I sent him a couple notes via private e-mail. I understand that drama is a no-no here. I agree. But here I was trying to help that soul and got welcomed by LG's message saying I "cannot do that"..

Let us see how long it takes for this thread to evaporate too.

Testing..1..2..3.....so far so good. In answer to the rare MV lamps inquiry I could write a book about them! Topping my list are the Westinghouse 175W MVs with PS-30 outer bulbs introduced in 1952-53. None found to date but they were produced. Same goes for the clear yellow-stained BT-37 400W lamps made by Westinghouse in the late 1950s. And my list goes on....

@ Joe Maurath, (I hate this new thing where you cannot reply with quote to the last response so annoying)
It's definitely not the same on L-G as it used to be years ago when I joined and even before that for the several years I used to browse the site before becoming a member. So much drama nowadays here when there shouldn't be.

But the first lamp that I think of when it comes to rare lamps is those "caution yellow" MV lamps. Those I've heard are impossible to find.

@ Ryan... It was not a matter of not being able to respond to a last post. Someone(s) in the admin team    pulled the plug on what Morbid Angel (Jamie) had to say not long after he made his postings. He did not say anything wrong from what I recall; he was emotionally reaching out and saying things the way they were. I am very glad I saw his words here before they evaporated; and that I sent him some encouragement and advice separately by private e-mails to help the dude out through some tough times he has been having.

The above is off-topic but below is not. Lets see how long it takes for the  to edit

Back to rare MV lamps, there are several of the purple-stained DX ones out there along with a scant few yellow /Y ones. The Westinghouse yellow MVs were outside stained. The GE yellows had a fired-on yellow heat-resistant finish (covered from top-to-bottom). Sylvania used a special yellow phosphor. Amplex listed /Y lamps (175W and 400W) in the 1960s and those also were coated inside with a special yellow phosphor; I think Sylvania made them. All /Y lamps as far as I know were 400W except for the forementioned Amplex 175W ones.

I'd say that the /X and the /Y lamps are probably the rarest of the rare !!

 @ Joe Maurath : You did see Owen's (HomeBrewLamps) Westy 100w /X , right ??

@ Joe, no I wasn't talking about Jamie's situation I was just stating that it was not letting me quote your response to the topic. The admins changed some settings so that the button to "Reply With Quote" doesn't appear if you are replying to the most recent response. That's what I'm saying is annoying these little ridiculous changes they're making like that. I like to quote so that whoever I'm replying knows I'm replying to them and not someone else.

I need to acquire both of those lamps though I'd pay good money for them I know they're rare. The purple stained and the yellow caution lamps.

  I got few rare MVs in my collection

   100 watt Westinghouse BLB
    EH1 400 watt westy
    1000 half coater /w H36
     1000 watt H34/W westy with E40 Export cap
     100 watt T10 tubular lifegaurd lamp
       Westinghouse 1000 watt beauty tone /R

       Now on british side MV

       Is the Mercra 80 watt Inside frosy Peal lamp
       And clear siemen surray mercury lamp
 

There are also the types of lamps that might be rare in one country but common in another. For example during the heyday of MV, most of the American Big 3 lampmakers setup domestic production facilities in Canada to produce MV lamps so even though the US and Canada share the same technical standards for MV lamps, the lamps sold in each country were different. For that reason it's rare to see a clear banded MV lamp in Canada and it's also rare to see a cleartop made during the 1980s in the US.

Some other rare mercury vapor lamps for the North American market include 1000w H34 clear mercury vapor lamps and also 1000w R80 mercury vapor lamps (1000w H34 mercury vapor R80 lamps are even rarer than the 1000w H36 mercury vapor R80 lamps).

For me, it has to be the MAT/V blended medium pressure lamp. That truly is the holy grail of MV lamps to me. I have missed out on no less than three on eBay over the years, due to auction prices going through the roof, the last one sold for well in excess of £300 if I remember right 

What chance do ordinary people have against people with bottomless pockets..?