One of my close friends when I was a teenager was a gentleman who repaired jewelry and watches. His father had been a jeweler and was a lapidary.

He told me that when he was in the first grade, there was a test that contained the following question:

How many legs does a lapidary have?

He was the only kid in his class who did not answer "four."

First thought: Ha!
Second thought: Grade one!!! Standards were high - or the teacher had a twisted sense of humor.

One step from lapidary father to mother-of-pearl and the word is a little bit odd. I looked at the online etymology:
mother of pearl

1510, translating M.L. mater perlarum, with the first element perhaps connected in popular imagination with obsolete mother
a thick substance concreting in liquors; the lees or scum concreted" [Johnson], which is from the root of mud.

I really don't know how to read this line.

(it ís the shiny surface of the inside of oysters and shells, isn't it?)

I stand to be corrected and have not looked it up before
posting like I suppose I should, but I thought that was
nacre.

mother-of-pearl
The pearly internal layer of certain mollusk shells, used to make decorative objects. Also called nacre. - AHD4

Yes, I looked up that word too, before I went to the etymology, but what puzzles me in the word is why mom in involved in this.

One possibility is that the Middle Latin mater in the mater perlarum is a corruption of Latin materia and it got folk-etymlogized to meaning mother. The nacre was assumed, just by its appearance, to be related to pearls, hence 'material of pearls'.

In NZ the Paua shell is used for Jewellery. It is very beautiful and full of iridescent green, blue, orange, silver, purple and sometimes pink colours. The Paua has edible 'meat' which you might know by the name Abalone. The outer shell is plain ugly, underneath is the 'foot' (flesh) and you see this Haliotis iris. Lapidary workers will grind back the outer crust and the whole shell can be used for making things Jewelry Box

The interior shell of the Paua is also referred to as NACRE. And they also can produce a natural pearl.

I'm glad at least I was on the right track.

Good grief--I first read that as Halitosis iris. Phew!

but what puzzles me in the word is why mom in involved in this.

Imagine a grain of sand entering a shell. The Nacre is secreted from within the cells shell encasing the grain with multiples layers and 'viola' a pearl is born.

Sounds reasonable and how beautiful the colors and that little row of holes in the shell !

Those little holes are natural, Bran.

And I have been reading up about pearls since this subject started and here are two facts I found interesting

momme is the measurement used for weighing pearls... looks like 'your mom' was involved in this again
1 momme = 3.75 grams or 3750 milligrams.

and

Did you know that caviar, should be served with a non-metallic spoon. This is because a metal spoon is said to transfer a metallic taste to the caviar.
Spoons made from bone or mother of pearl are preferred.

That would explain why that peanut butter and caviar sandwich I had so many years ago didn't taste very good. I spread the caviar with a metallic knife.

peanut butter and caviar sandwich Now, what'd you want to go and ruin perfectly good peanut butter for?

With a ketchup milk shake.

Momme raths?

outgrabe