But Evelyn's most important lesson had nothing to do with diamonds.
One afternoon, a wealthy customer entered the workshop and spoke dismissively to a teenage assistant.
The woman demanded that the girl clean a necklace while insulting the way she spoke.
Evelyn stepped from behind her workbench.
"Ma'am, you're welcome to have your necklace repaired here."
The woman nodded impatiently.
"Then tell the girl to hurry."
Evelyn remained still.
"But you are not welcome to humiliate my employee."
The customer stared.
For a moment, she seemed unable to believe a small business owner would challenge her.
Then she threatened to take her jewelry elsewhere.
Evelyn nodded.
"That's your decision."
The woman left.
Diana watched from the back of the workshop.
Later, she asked her mother whether they could afford to lose customers.
Evelyn smiled sadly.
"Not always."
"Then why did you let her leave?"
Her mother put down her tools.
"Because if I build a business where people have to surrender their dignity to keep their jobs, I haven't built anything worth being proud of."
Diana never forgot those words.
When Diana graduated from college, she had already decided that she wanted to help expand her mother's business.
She studied finance and marketing, then spent several years working for a major luxury retailer. She learned how international supply chains operated, how expensive products were priced, and why customer relationships mattered more than an impressive storefront.
She also saw the industry's ugly side.
Some salespeople were trained to make assumptions about customers based on clothing, appearance, age, and perceived wealth.
Others were rewarded for cultivating a narrow group of clients while quietly discouraging people who didn't fit the image management wanted.
Diana disliked those practices.
She also understood that a luxury store needed real security procedures, appointments for certain collections, and careful controls over valuable merchandise.
But none of those necessities required humiliating customers.
Security could be professional.
Appointments could be verified.
And expensive items could be protected without treating certain people as inherently suspicious.
When she returned to her mother's workshop, Diana brought a detailed business plan.
Evelyn laughed when she saw the presentation.
"Forty-two pages?"
Diana smiled.
"Forty-seven, including the financial projections."
Her mother shook her head affectionately.
"I taught you to make jewelry, not write novels about it."
They spent the entire weekend discussing the plan.
Diana wanted to develop an online catalog, invest in a more professional showroom, and establish relationships with collectors who appreciated original design.
Evelyn worried about debt.
She had spent too many years watching businesses fail because they expanded faster than their finances allowed.
Diana understood.
So they began small.
They photographed the collection.