Dead Guilty

late?’’
‘‘I’m making some thin sections for Dr. Lymon.’’
‘‘You wouldn’t happen to know anything about gemstones, would you?’’
‘‘My speciality is mainly sedimentary stratigraphy and crystallography. However, as it happens, I do know quite a bit about gemstones. What stone are you interested in?’’
‘‘Diamonds.’’
‘‘Nice choice. What about them do you want to know?’’
Diane was glad he didn’t make that girl’s-best-friend joke. She would have been disappointed in him. ‘‘Ex pensive, aren’t they?’’
‘‘Can be very expensive. Depends on the quality. Diamonds are graded for their cut, clarity, color and carat weight. In diamonds, size does matter.’’ He grinned. ‘‘You in the market for a diamond?’’
‘‘This information is for the crime lab.’’
‘‘Great. Does this mean I can put forensic gemology on my resume?’’
‘‘Depends on how helpful you are.’’
‘‘I’m here for you, Boss. What you need to know?’’
‘‘I suppose I want to know if the person who pur chased it could afford it, however, at the time, I didn’t think to ask the woman how much it cost.’’
‘‘Okay, we’ll start with the easy stuff. What color was it?’’
‘‘Diamond colored.’’
‘‘You don’t know about diamonds, do you? Never had an engagement ring?’’
‘‘Yes, I have. It belonged to my ex-husband’s grand mother and was a ruby with two diamonds on either side.’’
‘‘I didn’t know you were married, Boss.’’
‘‘When I was very young—still a university student. It didn’t last long.’’
‘‘One of those quick, passionate affairs that fizzled?’’
‘‘No. He was a lawyer selected by my parents. It turned out I didn’t like him very much.’’
‘‘Your parents selected your husband? What cen tury are you from?’’
‘‘It was the last time I tried to please my parents. It was a lost cause. I was simply the black sheep of the family, and I learned to accept it. Now that you know my history, can we get back to the diamonds?’’
‘‘Your history? That was just the teaser.’’ ‘‘Mike.’’
‘‘Okay, Boss. Come this way.’’ He led her into the geology lab adjoining the rock room.
‘‘This is part of our reference collection of gems. Have a seat and I’ll give you a lesson in Diamonds one-oh-one.’’ He went into the storeroom and came out with a large flat drawer and set it on the table.
‘‘With some exceptions, white diamonds in general are the most valuable, and they’re graded on a color scale from white—colorless—to yellow,’’ said Mike. ‘‘They do come in other colors, but for the most part they aren’t as valued, unless the color is quite brilliant. For example, the pink diamonds from Australia, and some of the high-carat famous diamonds like the Hope diamond are very rare and very valuable. A red diamond can be a million dollars a carat. But here, I take it, we’re dealing with the white diamond.’’
‘‘Yes.’’
‘‘Did it have a yellow cast that you noticed?’’
Diane shook her head. ‘‘No. It was really a beautiful stone. It had a traditional round cut.’’
He shook his head. ‘‘Cut doesn’t refer to shape, but the quality of the cut. Not all diamonds are cut kindly.’’
‘‘You are enjoying this, aren’t you?’’
‘‘I am.’’
‘‘Doesn’t the rock room have a computer exhibit on diamonds?’’
‘‘Yes, it does, but it’s not nearly as interactive as I am.’’
Diane shook her head and laughed.
‘‘I made you laugh. I’m making progress.’’ Mike took a clear plastic container from the tray, removed a stone and held it in his hand. ‘‘Diamonds have a high refractive index. You want a cut that reflects the light out of the top of the stone and doesn’t let light leak out the bottom.’’
‘‘Leak out the bottom?’’
‘‘It has to do with the angle each facet is to the others. In an ideal cut, the arrangement maximizes the light’s ability to disperse throughout the stone and reflect back out the top. A good-quality diamond can be ruined by a bad cut. When you said the diamond looked like a really good diamond, you were probably referring to how it glittered.’’
Diane thought a moment and met his gaze. ‘‘You’re right. It sparkled.’’
‘‘How large was it?’’
Diane looked at her hand, visualizing Kacie’s ring. She was fairly good at estimating measurements, hav ing measured so many