BEIJING -- China's consumer confidence declined in June partly due to drastic stock market fluctuations, according to an index released Thursday.

The Bank-card Consumer Confidence Index (BCCI), compiled by Xinhua News Agency and China UnionPay, a national bank card association, stood at 83.58 points in June, down 0.41 points from May and down 1.69 points from June 2014.

A higher index reading shows an increase in consumers' desire to spend.

Spending on non-necessities dropped sharply, with a plunge of 18.85 percent for jewelry and handicrafts, and 37.22 percent for suitcases and leatherware.

A report released along with the index attributed the drop in confidence mainly to fluctuations in earnings from personal investment holdings.

China's stock market peaked in the middle of June but has since fallen sharply, with the benchmark Shanghai Composite Index dropping 7.25 percent during the month.

Continued volatility of the stock market may lead to further fluctuations of the BCCI, the report said.

The BCCI, first released in April 2009, is based on bank card transaction data and analyses of changes in urban consumption.