White-metal watches steel and platinum are hot. The white-watch trend has spawned a surge in watches made with titanium, the so-called 'space age' metal. Titanium watches are not as numerous as steel or even platinum, but you see more now than ever before and still more are on the way. So what is titanium? What do you need to know about it to talk knowledgeably to customers? The following briefing should help.

by Joe Thompson

Titanium is a metallic element found in the earth's crust. The element occurs as a bright, lustrous metal or a silver-gray or dark gray powder. Its compounds are found in practically all igneous rocks and their sand deposits.

Titanium has a number of characteristics that make it valuable for industrial and commercial use:

- It's strong: Titanium is 30% stronger than steel.

- It's light: Titanium weighs in at 47.90 on the atomic scale, nearly 50% lighter than steel. -It resists corrosion: When exposed to the atmosphere, titanium forms a tight, tenacious oxide film that resists a variety of materials that corrode other metals. It is especially resistant to salt water corrosion.

Not exactly. The first mention of titanium in scientific writing occurred in 1791, when an amateur British scientist, William Gregor, analyzed some sand from Comwall and found "a reddish brown calx" he couldn't identify. He wondered if it was a new metal. Four years later an Austrian chemist, Martin Heinrich Klaproth, confirmed that Gregor had indeed discovered a new element. Klaproth named the element "titanium."

The development of titanium alloys for industrial use, however, is relatively new. Wilhelm Kroll of Luxembourg is recognized as the father of the modem titanium industry. In the 1930s, he developed a process to manufacture metallic titanium and refined the process in the 1940s. The Kroll method of manufacturing titanium metal is still used today.

The titanium metal industry emerged in the 1950s in response to demand from the emerging aerospace industry which used titanium to build jet planes.

Until the mid-1970s, more than 85% of titanium produced was used in the aerospace industry. Titanium's unique properties--density half that of steel, excellent strength retention to 1,000 degrees F and atmospheric corrosion immunity superior to that of other metals--made it ideal for the construction of the engines and frames of jet planes, rockets and space craft. The military uses the metal in weapons like guided missiles and recoil mechanisms in artillery.

Since the 1970s, the price of titanium mill products has dropped and the metal has been used in a wide range of industries. The most popular compound is titanium dioxide, common in the production of paint pigment, paper, plastics, glass and ceramics. jewelers might be interested to know that the ',stars" in star rubies and sapphires are due to the presence of titanium dioxide. Shipbuilders appreciate titanium's superior resistance to salt water and use it to make ship propellers, shafts and other parts. The Navy uses it on submarines.

No. It is the ninth most abundant element in the earth's crust. There is at least a 10,000year supply of titanium ore. Titanium has also been found in meteorites and moon rocks and is present in the sun and other stars.

Yes. The extraction of titanium from its ores is a relatively slow and costly process, which makes the metal expensive. For years the high cost of titanium limited its use to military and aerospace purposes.

Martin Heinrich Klaproth, the Austrian chemist who confirmed the discovery of the metal, named it after the Titans, the first sons of the earth in Greek mythology. Their mother was Gaea (Earth). They were a race of giant deities who ultimately were overthrown by the Olympian gods. They are associated with great size and strength--hence the word "titanic." The name is appropriate for an extremely strong element taken from the earth.

Titanium's unusual features present some distinct advantages to watch wearers. Citizen Watch Co., which says it is the world's largest manufacturer of titanium watches, points out that titanium is particularly well suited for sports and divers' watches. It urges retailers to be aware of the following points in dealing with customers:

- Titanium watches are quite comfortable because they are surprisingly light on the wrist. You can feel the difference compared to a steel watch.

- Titanium is hypoallergenic. It's nickel-free. Titanium watches can be worn comfortably even when the skin perspires.

- Because the metal is stronger than steel, titanium watches are more durable.

- The corrosion-resistance feature makes titanium particularly well suited for divers' watches. Titanium is environmentally friendly it conies from the earth and is recyclable.

Two. One is that titanium is more expensive than steel. The other is that titanium can be stained and scratched quite easily. Citizen, for example, compensates for this by using a patented "glass multi-layer coating" on its Promaster Titanium models which the company says makes them scratch-resistant