Gold and sapphire. No, we're not talking about Rolex wristwatches but the iPhone 5S. All rumors of course.
The reason? Sapphire prevents the button from being scratched and a slightly convex shape creates room for the fingerprint sensor, according to the analyst.
Note that there has also been speculation thatfingerprint sensing chores.
A fingerprint reader could pave the way for more secure mobile payments or be used as a more secure way to access a user's Apple account.
The "champagne gold" colored iPhone 5S rumor was reiterated by the Japanese site Macotakara on Sunday (a rumor it's reported before) here.
The KGI analyst also mentioned the new iPhone 5S will keep the 8-megapixel sensor but make other camera improvements.
Another notable iPhone 5S rumor has it sporting a new Apple A7 processor.