
The Diamond Authority
At The Diamond Authority, we believe in transparency and personalized service. With over 100 years of combined experience, Jeremy and Dave are the true authorities on diamonds and fine jewelry in Portland. As the most experienced jeweler in town that shows you the invoice for a GIA-certified mined diamonds, we take the mystery out of buying a diamond. Here, you won’t encounter any pushy salespeople—because you’ll be working directly with Jeremy and Dave, the owners, and experts behind The Diamond Authority.
What We Offer
Loose Diamonds
We are your local and trusted experts in earth mined & lab grown diamonds. We are the only jeweler in Portland that will show you the actual invoice of a GIA-certified earth mined diamond and guarantee you’ll only pay 20% above invoice. Come see us and find out why our customers love us and other jewelers hate us.


Custom Design
Unique bridal rings and tailor-made jewelry that you won’t find anywhere else.


Experience the Tower of Diamonds!
Take a private elevator ride to the 4th floor of Lincoln Tower on Greenburg Rd, right across from Washington Square. Experience the difference of working with seasoned professionals who bring their expertise and passion to every appointment, all while enjoying exceptional savings.
Client Testimonials
1000+ GLOWING REVIEWS
Patti Howard
Stratton Turpen
Will Harden
J.
Dan Woods
Brian Buckmier
Ken Steckler
Geralyn Wiechert
Duff Minor

Book Your Appointment Today
Ready to find your perfect piece? Schedule your visit and see why Jeremy and Dave are Portland’s top choice and your authority for fine jewelry.
A Century of Expertise
With over 100 years in the industry, our legacy of knowledge and skill ensures every piece is crafted to perfection.
Jewelry for Every Moment
Whether it’s a milestone celebration or a simple “just because,” our collection has something perfect for every occasion.
Diamonds for Every Preference
Choose between natural diamonds and sustainable lab-grown alternatives, each offering unparalleled beauty and brilliance to fit your values.