Here's my version, using stuff I had on hand.
Unfortunately, we didn't have a suitable solar panel and my husband wasn't up for running to the local supplier for one, so I have to wait a bit before it's completely finished to my liking. I designed the shape so the small solar panel can rest on the back at an angle and charge during the day if one leaves it in a sunny windowsill.
I wanted the mushrooms to resemble the real luminous mushrooms and glow for awhile after it was turned off.
Step 1: Prepare the log
A smooth, decaying stick I found in the strawberry bed seemed aesthetically pleasing... but all the cracks almost guaranteed lots of bugs.
The maple branch I'd removed from our tree a few weeks ago was almost certain to have very few things that might crawl out and bite me, but it just wasn't very interesting to look at.
Finally, I decided on the root end of some evergreen bushes I recently ripped up. I didn't see any holes where bugs might be hiding, and it was definitely interesting to look at. I washed it with the hose, broke off the extra branches, and dried it in the oven at 200 degrees for a couple hours. That way, any bugs would hopefully die.
I then drilled holes where I thought mushrooms should go.
I decided to put the wiring etc in the back, rather than hollowing out part of the log. The solar panel would have to be visible, anyway.
Step 2: Make the mushroom caps and stalks
I wanted to create a subtle stripe effect instead of just mashing the two together.
I rolled out a log of each color then sliced them in fourths. I placed the sections next to each other to make a shorter, fatter log, then squished them together and rolled them out again. I repeated this a couple more times until the stripes were as thin as I liked.
I left the log thick and sliced off sections to make the caps. I pinched the outsides of the slice together into a point to form the top of the mushroom cap so the stripes would line up properly. I smooshed a handle into the bottom of the cap to hollow it out a bit, then pressed a blade into the cap to form lines inside and out.
I used two enameled copper wires for each stem. I rolled out a small log of the striped clay, flattened it, then wrapped it around the wires; the long ends of wire protruded from the bottom of the stem. I squished the clay up from the bottom of the stem a bit to make it slightly fatter. I bent some of the stems just a little to make them more interesting.
The tops of the caps and the bottoms of the stems could use some color. I'd have used a flat brown brush on pigment powder if I had any, but all I had was metallic copper or silver powder. I used those. I like shiny.
On one of the mushrooms, I decided to use something flatter. I went outside and grabbed a little dirt. The dirt has larger particles than the pigment, so I really had to press it into the clay. I could've scraped some brown chalk with a knife and used that powder, but I couldn't find it.
I baked these at 275 degrees for about 15 minutes.
Step 3: Assemble the lamp
My husband helped with the next part. Because we were doing detailed stuff, I asked to use his iphone to take pictures instead. My new one hasn't shipped yet, and the iphone 4 takes much more detailed pictures than my old one. Unfortunately, his phone crashed half an hour after we finished the lamp and he lost everything recently added. I'm really sorry about the lack of pictures. Yes, we do have a real camera... somewhere... I probably couldn't find the cord to save my life, though...
We scraped the enamel off the ends of the wire. Then we coated the wires with flux and soldered a white surface mount LED to the top of each mushroom stalk. I had only used one color of wire on each stalk, so we had to test the long ends to find out which was positive and which was negative. We attached a resistor to each positive wire... it was tan with two red bands and a brown one. I forgot the numbers, but I'm sure you can look up what type of resistor to use based on your specific LED setup.
Because we don't yet have the right solar panel, we just hooked up two AAA batteries to light the thing up. Once we get the solar panel we can put in a rechargeable battery and solder everything together.
After the LEDs were soldered in place, I squirted some hot glue into each mushroom cap, held it upside down for a few seconds so it wouldn't drip out, then squished it onto a stalk.
Step 4: Charge and admire
I would recommend spraying with a clear sealant after everything is assembled; it's good to protect the wood. I haven't done this yet. I considered painting the white fungus on the wood with glow in the dark paint, but I haven't decided whether or not I will.
My iphone doesn't do a very good job of picking up the glowing mushrooms after the LEDs are off. They do glow pretty well, and the stripes of glow clay and translucent clay are more visible in person.
Thanks for looking! I hope you try your own.