Schott or Ohara currently offering fluorite?

Hi. I was wondering whether presently or even anytime recently (last 5 years) either Schott or Ohara were producing true fluorite blanks (i.e., not low dispersion glass such as FPL-53 which has some fluorite in its formulation, but actual CaF2 crystal blanks)?

I'm interested in smallish ones in the 4" and under size, in particular. I remember when William Optics used to advertise small ED-glass optics as "fluorite", and have a feeling another vendor may be doing the same now.

I'm just trying to separate the "fact" from the marketing malarkey. Thanks in advance for your help!

Regards,

Jim

Crystal fluorite is widely available from several sources in the U.S., Germany, and China. Large blanks up to 14" are used in optics that operate at UV wavelenths in the lithography machines that process semiconductor wafers.

That said, even "crystal" fluorite can have lattice defects or inclusions that make it unsuitable for precision optics. For an objective lens, it has to be graded and selected just like any other glass.

I'm interested in smallish ones in the 4" and under size, in particular. I remember when William Optics used to advertise small ED-glass optics as "fluorite", and have a feeling another vendor may be doing the same now.

Jim:

I have an 80mm William Optics Megrez II FD. The objective clearly states Fluorite Doublet.

However, several years ago it was made clear that these objectives as well others that William Optics termed Fluorite were not Fluorite, in my case it was actually FPL-53. I believe the LOMO triplets were also called Fluorite but were not. I confirmed this in a recent Email conversation with William Optics.

Jon