Stephen Schwarzman is co-founder and CEO of Blackstone, one of the world's leading investment firms. His investments in hundreds of companies around the world have earned Schwarzman a net worth over $18 billion.

Schwarzman has conducted thousands of job interviews over his career to select the very best candidates to join his team. In his new book, What It Takes: Lessons in the Pursuit of Excellence, Schwarzman offers job candidates eight rules for having a successful interview.

Since his tips also speak to what Schwarzman is looking for in a job candidate, the rules give employers a guide on how to be a "strong assessor of talent." 

1. Be on time.

"Punctuality is the first indicator of how much thought and preparation you have put into an interview," writes Schwarzman.

Arriving on time--even early--gives you the opportunity to relax, take a breath, and take in the atmosphere. Are employees walking in the office with a frown or a smile? Are they friendly or surly? The environment is talking to you, but if you get there too late you won't have time to listen.

2. Be authentic.

Share you who are, says Schwarzman. If the interview doesn't result in a job offer, the organization probably wasn't the right fit for you. It's better to know early and move on. Don't change your personality to fit the culture. Find the culture that's right for you. If you're in the hiring position, ask casual questions before jumping into the your prepared interview questions. 

3. Be prepared.

Learn about the company. If you're a job candidate, it shows the hiring manager or recruiter how enthusiastic you are about the company. In an article I wrote for earlier this year, I featured JPMorgan CEO, Jamie Dimon, who says he won't hire a person if they haven't read his annual letter to shareholders. One of the easiest--and overlooked--preparation tips is simply to read a book or paper published by the company's CEO or a notable stakeholder in the company.

4. Be candid.

"Don't be afraid to talk about what's on your mind." Don't focus on 'impressing' the interviewer. Strive for an honest conservation, instead. If there's something about the new company or role that you have a reservation about, bring it up now. The hiring manager might have a good answer for you. 

5. Be confident.

"In most situations, employers are looking for someone who can hold the table." Hold the table--means you have an opinion and you can build a case to defend it.

Some of the people I know in Silicon Valley worked at Apple for Steve Jobs. Jobs was a tough manager, but he respected people who could hold their own in a conversation. When I wrote a book about the Apple store, I learned that hiring managers often asked detailed tech questions, but not because they expected a correct answer. They wanted to hire people who had the confidence to admit that they didn't know the answer. An ideal job candidate demonstrates a plan to find the answer to a question they don't know. 

6. Be curious.

The best interviews are interactive, writes Schwarzman. "Ask questions, ask for advice, ask your interviewers what they enjoy most about working for their organizations." The best advice I've heard about curiosity is from Microsoft CEO, Satya Nadella, in his book, Hit Refresh. A curious person is a "learn-it-all" and not a "know-it-all," Nadella says. 

7. Avoid discussing divisive political issues.

If you haven't learned this rule by now, I'm afraid the other seven won't help you.

8. Mention people you know only if you like and respect them.

Don't just drop names of people at the company for the sake of name-dropping. According to Schwarzman, your interviewer will be judging your taste in people. I do some company name-dropping if I'm speaking at an organization, but I do my homework first. Before I bring up the name of a particular person in front an audience, I make sure that person is truly admired and respected within the company. 

Impressions matter, says Schwarzman. Potential employers, and even customers, partners and investors will be evaluating you for all sorts of clues. Following these eight rules will win over them over.