EF5/6 Coin sentence combining

COMBINE
A coin is a piece of metal that has a certain weight. It has the mark of the people who issued it.

DECIDE WHAT STYLE YOU WANT: SIMPLE COMPOUND COMPLEX
FEELING FOR IT, A SENSE OF WHAT MIGHT WORK BEST

A coin is a piece of metal that has a certain weight. It has the mark of the people who issued it. 
A coin, which has the mark of the people who issued it, is a piece of metal that has a certain weight. COMPLEX
A coin, which has the mark of the people who issued it, is a piece of metal with a certain weight.
GOOD STYLE
A coin is a piece of metal that has a certain weight and the mark of the people who issued it.

This is good sentence writing!

2. The Lydians were a powerful people in Asia Minor who needed a convenient method of receiving payment for products they produced; for that reason, in the seventh century B.C, they made the first primitively-made coins which were composed of "electrum", a natural composition of gold and silver.

3. The Greeks saw these coins and appreciated their usefulness, so they began to make coins, too.

4. About 100 years later, many cities in Greece and all over the mainland Asia Minor had them, too.

5. Gold coins were the most valuable, but silver and copper were also used. The Romans later adopted the idea, carrying it on for 500 years, when the art of coinage declined.

6. In the fifteenth century, the art of coinage was revived because there was more metal available and also because there were many skilled artisans
to engrave the coins in this period of history.

7. The first coins made in America, in 1752, were not (of) regular shape or weight.
preposition usage  not of
"The sweater is not high quality."
"The sweater is not of high quality."
The first coins made in America, in 1752, were not regular in shape or/and weight.

When it's negative, we don't say 'and'. We use 'or'.
I don't speak German and French. XXX
I don't speak German or French.
Mary speaks German and French.

The first coins made in America, in 1752, were not regular in shape or the same weight.

-not regularly shaped or the same weight.

neither nor LOW FREQUENCY
She speaks neither French nor German. VERY FORMAL
She doesn't speak French or German. NATURAL
I cannot pick you up or drive you to work.

Sarah has never visited Japan or Thailand. NATURAL
Sarah has never visited Japan nor Thailand. FORMAL
Sarah has visited neither Japan nor Thailand. VERY FORMAL




8. Today coins are essential in our modern life; in fact, our society, with its vast number of coin-operated machines, could not function without this ancient invention.

LONGER STYLE SENTENCES