The British Crown Jewels are lousy with them -- and we mean that in the best possible way. After all, this very classy precious gemstone has long been linked with exalted leaders, from kings to high priests. We speak, of course, of the:

Sapphire.

Rich rose-colored diamond.

Emerald.

OK, sapphires are typically a deep blue. That's a given. But they also come in all the following colors except which one?

Pink.

Red.

Yellow.

Generally speaking, the most valuable rubies are those that:

Have a deep violet cast -- a la Liz Taylor's eyes.

Have a fiery orange core.

Are pure red -- or red with just a hint of another hue.

Which country is a rich source of fine-quality rubies?

Union of Myanmar (formerly Burma).

Canada.

Mexico.

OK, we've been flinging the word ''carat'' around here a bit, and it's often loosely used by both those in the biz as well as consumers to describe a couple of different characteristics of stones that indeed are related; but strictly speaking, what does it denote?

Size.

Weight.

Clarity.

It's the name of a cut! It's the name of a stone! It's two -- two -- entities in one! It's the:

Emerald.

Opal.

Funky Chicken.

Emerald is the birthstone for those lucky enough to be born in the month of:

May.

June.

September.

Anything beyond the most trivial flaws in a stone can be seen by a sharp-eyed consumer armed with a good pair of reading glasses or a magnifier. Your own two eyes don't lie -- and they're the best judge of quality.

True.

False.

All right, let's test your pearls of wisdom. A key indicator of a pearl's quality is the richness of its luster, which is generally dependent on the thickness of its:

Nucleus.

Nacre.

If you rub a pearl gently against your teeth, and it feels ever so slightly rough or ''grainy,'' that's a fair indication that the pearl is:

Fake.

For real.