But before the cashier accepted the coin, she threw it on the counter and listened to the sound.
"She finally concluded it was OK," said the 25-year-old sales manager.
An increase in the number of counterfeit two lat coins has made this a familiar sight throughout Latvia as clerks try to make sure they are getting real currency.
Another popular technique is to rub the edges of the coin on a white sheet of paper. If a line is left, the coin usually is not accepted.
To combat the growing problem, the Central Bank of Latvia has stopped issuing two lat coins that display an image of a cow and is gradually replacing them with a coin that features the symbol for the god of fertility.
The coins with the cow image are still valid, but there will be less of them in circulation.
The bank's actions appear to have restored confidence in the two lat currency.
"I have noticed a lot of coins without a cow lately," Mironova said. "I kind of trust them."
The bank has been battling counterfeit currency since the introduction of Latvia's own currency in 1992.
During the last five years 38,000 lats in fake currency, of various denominations, have been taken out of circulation.
But the problem has increased dramatically in the last year. Almost half of the money taken out of circulation in the last five years, about 16,000 lats, was withdrawn in 1998.
The denomination of choice for counterfeiters lately appears to be the two lat coin.
"There used to be a problem with paper notes a long time ago," said Agita, a clerk at a food store in Riga's Old Town. "Now the problem is with coins."
The situation in Latvia is no worse than that in the other Baltic states, according to Andris Taurins of the Central Bank's Treasury and Money Circulation Administration.
The favorite currency for counterfeiters in Lithuania is the 20 lita bill while in Estonia it is the 100 kroon note, Taurins told the LETA news agency.
Most shopkeepers have become experienced at identifying forgeries and are not reporting any difficulties.
"There have been many cases [where a customer tries to use a fake two lat coin] but I always detect it and give it back," said Agita.
The manager of a nearby photo shop on Audeju street, Vineta, reports a similar success rate.
"I have been in sales for many years," she said. "There has never been a case where a coin was accepted which later turned out to be counterfeit."
Customers have become equally perceptive.
"You notice it [that a coin is fake] right away," said Miranova who reports she has become more cautious since accepting a fake two lat coin at an outdoor market two years ago. "It is light, it is not like normal currency, it is like Lithuanian coins, it feels like paper."
The Central Bank intends to monitor the situation closely.