Diamond Mountain Mining is a 187-acre collector’s mine for Herkimer diamond quartz crystals located in the hills of Little Falls, New York. At the time of its 2020 purchase, it was the last large undeveloped Herkimer-diamond-bearing parcel in Herkimer County, the only place in the world where these particular quartz crystals form. Mining access is by reservation only. Visitors who cannot book a dig can still shop for Herkimer diamond crystals in person at The Diamond House Crystal Gallery, the operation’s retail gallery in Little Falls (open to the public on Tuesdays).
This page covers what Diamond Mountain is, what you can dig for, how it differs from the more famous walk-in mines in Middleville, and where to stay if you are planning a visit.
Location and Access
Diamond Mountain Mining, Ltd.
416 Ritter Road
Little Falls, NY 13365
Herkimer County
Mining access is by reservation only. This is not a walk-in tourist mine. To book a dig experience, see the official Diamond Mountain Mining website.
The Diamond House Crystal Gallery (Retail Shopping)
For visitors who want to see and buy Herkimer diamond crystals without booking a dig, Diamond Mountain operates a separate retail gallery in Little Falls:
The Diamond House Crystal Gallery
5037 State Route 167
Little Falls, NY 13365
Herkimer County
Public Shopping Hours: Tuesdays 10:00 am – 4:00 pm, and by appointment.
This is the easiest way to see Diamond Mountain crystals in person if your visit does not coincide with an open dig reservation. The gallery is at a different address than the mine itself.
What You Can Dig For
Diamond Mountain is known for rare collector-grade Herkimer diamond forms that are difficult to find at the more commercial mines:
- Black stem scepters (Diamond Mountain calls itself “the home of the Herkimer Diamond Scepter”)
- Barbells (two crystals joined end-to-end)
- Hydrocarbon-included “black diamond” quartz
- Cathedral-like skeletal crystals
- Complex Herkimer diamond forms
- Classic clear doubly-terminated gems
These crystals are approximately 450 million years old.
The Property
The 187-acre Diamond Mountain property includes:
- Multiple dig sites
- Forest trails
- A spring-fed waterfall
- Views of the Mohawk River
It is a working commercial mine that also hosts paid dig experiences for visitors.
How Diamond Mountain Compares to the Famous Herkimer Diamond Mines
The more widely-known Herkimer Diamond Mines in Middleville (about 15 minutes north of Grand Colonial) is the family-oriented, walk-in version of the Herkimer-diamond experience. Diamond Mountain is different:
- Middleville mines: walk-in, family-oriented, broader visitor experience, gift shop, on-site campground
- Diamond Mountain: reservation-only, geared toward serious collectors, rare specimen forms (scepters, black diamonds, skeletal crystals)
If you are visiting Central New York specifically for Herkimer diamonds, doing both on the same trip is reasonable, with Diamond Mountain as the destination for unusual collector specimens and Middleville as the broader visitor experience.
Online Live Sales
If you cannot make it out for an in-person dig, Diamond Mountain runs regular online sales of mine-sourced crystals plus mineral specimens from around the world:
- Mondays at 6 pm ET: Retail live sale on Facebook
- Wednesdays at 5 pm ET: Theme shows on Facebook
- Thursdays at 12 pm ET: “Mineral Lunch Hour” on Instagram
Their event schedule is on the official site.
Where to Stay
Grand Colonial Bed and Breakfast in Herkimer is the most central full-service B&B for a Diamond Mountain visit. About 15 minutes from the mine, on a quiet residential block in Herkimer.
- Four guest rooms, each with private bath
- Full hot homemade breakfast every morning, time arranged at check-in
- All rooms pet-friendly, no extra cleaning fee
- $10/night discount for return guests on direct bookings
See our lodging near Little Falls guide for area overview, or check availability and book direct.
Buy Diamond Mountain Crystals at Grand Colonial Mercantile
Through our local relationship with Diamond Mountain, the Grand Colonial Bed and Breakfast Mercantile (our on-site gift shop) carries authentic Herkimer diamond crystals sourced directly from the Diamond Mountain mine. Guests get special pricing we secured through that relationship.
If you are visiting Diamond Mountain or the famous Middleville mines and want a take-home piece that does not require a half-day dig commitment, browsing the mercantile during your stay is the easiest path. Stones are authenticated and priced fairly relative to the broader Herkimer-diamond retail market.
Frequently Asked Questions
Where is Diamond Mountain Mining located?
416 Ritter Road, Little Falls, NY 13365, in Herkimer County. About 15 minutes from Grand Colonial Bed and Breakfast in Herkimer.
Do I need a reservation to dig at Diamond Mountain?
Yes. Mining access is by reservation only. Book through the official Diamond Mountain Mining website.
Can I shop for Herkimer diamonds at Diamond Mountain without a dig reservation?
Yes. The Diamond House Crystal Gallery at 5037 State Route 167 in Little Falls is open to the public on Tuesdays 10:00 am – 4:00 pm (and by appointment). The gallery is at a separate address from the mine itself.
Can I buy authentic Diamond Mountain Herkimer diamonds without visiting the mine?
Yes, through two paths. The Diamond House Crystal Gallery at 5037 State Route 167 is open Tuesdays 10am-4pm and by appointment for walk-in retail. Grand Colonial guests can also buy authentic Diamond Mountain Herkimer diamonds at our on-site mercantile, with special pricing through our local relationship with the mine.
How is Diamond Mountain different from the Herkimer Diamond Mines in Middleville?
The Middleville mines are walk-in and family-oriented. Diamond Mountain is reservation-only and geared toward serious collectors, with a focus on rare specimen forms like scepters, hydrocarbon-included “black diamonds,” and skeletal crystals.
What kinds of Herkimer diamonds are found at Diamond Mountain?
Black stem scepters, barbells, hydrocarbon-included “black diamond” quartz, cathedral-like skeletal crystals, complex multi-crystal forms, and classic clear doubly-terminated gems. The site is known particularly for scepters.
Can I buy crystals without visiting in person?
Yes. Diamond Mountain runs weekly live online sales on Facebook (Mondays 6pm ET retail, Wednesdays 5pm ET theme shows) and Instagram (Thursdays 12pm ET “Mineral Lunch Hour”).
How old are Herkimer diamonds?
Approximately 450 million years old. The Herkimer diamond quartz crystals at Diamond Mountain (and the broader Herkimer County region) form only in this one geological formation, found nowhere else in the world.
Planning a Diamond Mountain visit?
Grand Colonial Bed and Breakfast in Herkimer is about 15 minutes from the mine. 4 rooms with private baths, full hot homemade breakfast, pet-friendly, $10/night return guest discount on direct bookings.