"Andy Dingley" wrote in message ...
| What are Van Dyke crystals made of?
|
| I thought I knew - walnut husks. Now I read in Sam Allen that it's a
| form of peat! Anyoen else heard this?

Van Dyke Crystals depending upon your pursuit is one of the following 3. I don't think we can count a "Van Dyke Laser Blast"

1. Bichromate of Potash - Woodwork -

brown pigments made from deposits of peat or brown coal, known primarily under the name van dyke brown, but also as Cologne earth or Cassel earth (after the German cities Köln and Kassel where the earliest and highest quality deposits of the pigment were mined), Kassel umber, Cullens earth or Rubens' brown. (In French sources, the name van dyke brown often refers to a calcined yellow ochre.) The pigments were first mentioned in early 17th century artists' handbooks, and were widely used in watercolors through the 19th century; the pigment is still mined today near Kassel.

Bichromate of Potash is one of the most important chemicals historically used in woodworking. Rather than dying the fibers (as with Aniline Dyes) or putting pigment particles on the surface (as with all "stains"), it reacts with the natural tannin in the wood. The depth of color that can be achieved is stunning. Comes as a powder and can be mixed in varying strengths with warm water to produce varying color intensities.

Van Dyke Crystals, which is a brown, has been a favorite of finishers for centuries. A natural substance, it can be used not only to color but also to shade or darken certain areas on the wood surface. Just add warm water to the strength that you need. It also come in a packet in powder form.

2. quartz crystals - Radio -

Karl S. Van Dyke proposed standards for describing the piezoelectric properties of quartz crystals.

3. Van Dyke Brown - Photography -

A) Ferric Ammonium Citrate 90 gm dissolved in Water 250 ml

B) Tartaric acid 15 gm dissolved in Water 250 ml

C) Silver nitrate 30 gm dissolved in Water 250 ml

Mix A & B then add C.

Add 5 ml Glyoxal

Add water to 800 ml




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PDQ

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What are Van Dyke crystals made of?

I thought I knew - walnut husks. Now I read in Sam Allen that it's a
form of peat! Anyoen else heard this?

"Andy Dingley" wrote in message
...
What are Van Dyke crystals made of?

I thought I knew - walnut husks. Now I read in Sam Allen that it's a
form of peat! Anyoen else heard this?

From: http://www.handprint.com/HP/WCL/pigmt1c.html

.. brown pigments made from deposits of peat or brown coal, known primarily
under the name van dyke brown (NBr8), but also as Cologne earth or Cassel
earth (after the German cities Köln and Kassel where the earliest and
highest quality deposits of the pigment were mined), Kassel umber, Cullens
earth or Rubens' brown. (In French sources, the name van dyke brown often
refers to a calcined yellow ochre.) The pigments were first mentioned in
early 17th century artists' handbooks, and were widely used in watercolors
through the 19th century; the pigment is still mined today near Kassel.
Holbein offers the natural organic pigment in watercolors.

Leif