Mood rings and go-go boots. Granny glasses and sea monkeys.

All mid-20th century fads that had their day and are now long gone and mostly forgotten.

At least one icon of that era has found a second life in the early 21st century. The aluminum Christmas tree. Ring out the old year and ring in the new with this question about a shiny family holiday heirloom.

Q. In a big box in the basement of our grandmother's house, we found this like-new, 6-foot aluminum tree several years ago. There also was a rotating multicolor light wheel. Now we set it up each holiday season. A guest this year suggested the tree was valuable and old. Can you tell us more? -- Sandy in Kennewick

A. Your guest was right. Classic aluminum trees are valuable and some people would call them old, even though they don't come close to meeting the commonly accepted definition of an antique as something at least 100 years old.

Aluminum trees came to the public's attention in 1959. Like many other fads, they caught on quickly and sales were brisk.

Most companies that made the trees -- and there were quite a few -- are long out of business and records have been lost. However, it's likely as many as 4 million of the trees were sold from 1959-69.

The largest manufacturer was the Aluminum Specialty Company of Wisconsin, which had been in the cookware business until the trees became their major product. Their top-of-the-line model was called "The Evergleam." Other companies in the metal tree business were Starlite, Regal Electronics and a California outfit called Fairyland Trees.

The trees nearly always were lighted from below, most often with the rotating color wheel light you have. Alternate illumination was important, because you couldn't string regular lights on these trees. One short circuit and the highly conductive aluminum could lead to a very warm Christmas!

Most fads fade from view as the public loses interest. Something else is thought to have led to the demise of America's aluminum trees. A cartoon.

A Charlie Brown Christmas first aired in 1965. In the show, Lucy urges Charlie to buy a "big, shiny aluminum tree ... maybe painted pink."

In an effort to preserve at least some of the spirit of the season and protest over-commercialization of the holiday, Charlie buys a small, scrawny natural tree. Afterward, aluminum tree sales started to tank. By 1968 they were hard to find and the last are thought to have been made in 1969.

Today's collectors have a different view. They see the trees not only as a symbol of mid-century American taste but as reflective of the style of that era.

The trees have been written up in Money magazine and Atomic Ranch magazine, the Portland-based journal of Mid-Century Modern style.

Enthusiasts seek out these trees and will pay pretty big prices for special ones.

Yours looks like a fairly common model in average-to-good condition. The fact you have the working color wheel adds value.

Several years ago a rare 7-foot pink tree sold on the internet for $3,600. Examples that will have a high price include colored or multicolored trees and those with unusual designs -- like pom-pom ends on the branches.

These trees came up to 8 feet tall and the larger ones, along with special models including a "half-tree" designed to hang on a wall and small desktop-sized trees, will bring a premium price.

As a rule of thumb, an average tree will sell for between $15 and $25 a foot. The color wheel adds from $100 to $200.

w Terry Maurer, a Tri-Cities personal property appraiser, is a member of the Certified Appraisers Guild of America. You may submit your antiques and collectible questions to What's It Worth by e-mail to whatsitworth@clearwire.net.