Rubicon Technology (RBCN) 10-K/A 2015 FY Annual report (amended)

EXHIBIT 31.4

Certification pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

I, Mardel A. Graffy, certify that:

1. I have reviewed this Annual Report on Form 10-K/A of Rubicon Technology, Inc.; and

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report.

Date: April 29, 2016	By:	/s/ Mardel A. Graffy
		Mardel A. Graffy
		Chief Financial Officer