1.83 ct Natural Unheated Ruby – Cushion Cut | GIA Certified

A natural 1.83 ct cushion-cut ruby, completely untreated, certified by GIA as a Ruby Origin Report (#6233835340) confirming Madagascar origin and no indications of heating. Untreated ruby — corundum that has never been heated — is among the most rare and collectible gemstones available in the loose stone market. Heat treatment is standard practice for virtually all commercial ruby (some estimates place this above 95% of the market), so a GIA-documented untreated ruby above 1 carat represents a genuinely exceptional find. The cushion cut at 1.83 carats produces strong face-up color in the purplish red range that fine ruby is prized for.

Rarity Analysis

• Untreated status: Well over 95% of commercial ruby on the market today is heat-treated to improve color and clarity. A stone with no indications of heating at all — confirmed by GIA rather than claimed by a seller — sits in a small minority of world ruby production.
• GIA Ruby Origin Report: Report #6233835340 is a Ruby Origin Report, meaning GIA independently confirmed species, weight, dimensions, treatment status, AND Madagascar origin in a single document. That dual confirmation — treatment and origin together — is a meaningfully higher bar than an undocumented "natural, Madagascar" claim.
• Above-1.5-carat size: Untreated ruby becomes progressively harder to find as size increases, since larger untreated rough is rarer and more likely to be heat-treated to maximize yield and color. At 1.83 carats, this stone clears a size threshold where untreated material is genuinely scarce.
• Purplish red color: This hue falls within the color range most associated with fine ruby, and the mixed cut (modified brilliant crown / step pavilion) is built to concentrate that saturation across the face-up view.
• Honest clarity note: This stone is graded Slightly Included, not flawless — a completely normal and expected clarity level for natural, untreated ruby of this size. Untreated rubies typically retain more of their natural inclusions than treated stones, since heating is often used partly to reduce the visibility of inclusions.
• Combined effect: Untreated status, GIA-confirmed Madagascar origin, and above-1.5-carat weight rarely appear together on a single stone. Individually each factor narrows the field; together, they place this ruby in a genuinely rare category within the natural colored stone market.

Buying Guidance

• Verify untreated status on paper, not on faith: Because heat treatment is standard practice for the overwhelming majority of commercial ruby, "untreated" is a claim that needs independent laboratory confirmation. Take any untreated claim seriously only when it is backed by a report from a major lab like GIA — as it is here.
• Origin documentation is a higher bar than an origin claim: A GIA Origin Report confirming Madagascar carries far more weight than a seller simply stating "Madagascar origin" with no laboratory backing. Ask to see the report, and confirm the report number matches the stone.
• Understand what clarity level to expect: Untreated ruby, especially in larger sizes, will typically show more visible inclusions than heat-treated material of similar size. A "Slightly Included" grade on an untreated stone is normal and should not be read as a flaw relative to the category.
• Care benefits of untreated ruby: Because this stone has never been heated or filled, it can be safely cleaned with an ultrasonic or steam cleaner — an option not recommended for many treated or glass-filled rubies, where heat or vibration can damage the filler material.
• Try Before You Buy: Request additional photos or a video call to view the stone's color and clarity in person before purchasing, and confirm return policy terms so you can evaluate the stone hands-on with confidence.

Learn More About This Gemstone

• Ruby — The Complete Buyer's Guide
• How to Read a GIA Lab Report
• Custom Ring Settings for Loose Gemstones
• The Smart Way to Buy Loose Gemstones Online

Why Choose this 1.83 ct Cushion Untreated Ruby?

The combination of three factors — untreated status, GIA documentation (Report #6233835340), and above-1.5-carat size — places this stone in the upper tier of natural ruby collecting. Untreated status means the color is entirely natural: no furnace, no glass filling, no enhancement of any kind. The GIA report confirms this independently, along with a Madagascar origin determination. At 1.83 carats, the stone has the weight for a dominant center stone in ring or pendant settings, and the cushion cut deepens the purplish red across the face-up surface.

Key Benefits of this Natural Ruby

• Untreated — GIA Confirmed
  No heat treatment, no glass filling, no enhancement. Certified untreated by GIA (Report #6233835340) — the most authoritative confirmation available.
• Exceptional Rarity
  GIA-documented untreated ruby above 1.5 carats is among the most sought-after colored gemstones in trade.
• 1.83-Carat Center Stone Size
  Large enough for a dominant presence in any engagement ring, cocktail ring, or pendant.
• Mixed Cut Craftsmanship
  A modified brilliant crown paired with a step-cut pavilion concentrates the deep purplish red saturation across the face-up surface.
• Durable for Daily Wear
  Corundum at Mohs 9, second only to diamond.

Features

• Variety: Ruby
• Carat Weight: 1.83 Carats
• Dimensions: 6.62 x 6.19 x 5.03 mm
• Shape: Cushion
• Cut Style: Mixed Cut (Modified Brilliant Crown / Step Pavilion)
• Treatment: Untreated — GIA confirmed (no indications of heating)
• Color: Purplish Red
• Origin: Madagascar (GIA determined)
• Clarity: Slightly Included
• Certification: GIA Report #6233835340
• Hardness: 9 on the Mohs scale

This 1.83 ct cushion untreated ruby has been hand-selected as an exceptional specimen — GIA-confirmed untreated ruby of this size and origin is the combination that defines the finest tier of natural ruby collecting.

One of a Kind

This is a single natural gemstone, not a manufactured or mass-produced item — no two rubies are exactly alike, and once this stone sells, this particular listing will not be restocked.

Care of Cushion Ruby

Ruby is durable (Mohs 9) but should still be cared for thoughtfully. Clean with warm water, mild soap, and a soft brush; since this stone is untreated and unfilled, it can safely be cleaned with an ultrasonic or steam cleaner if needed, unlike many treated rubies. Store separately from other jewelry to prevent surface scratches, and remove the stone before activities involving harsh chemicals or impact.

Why Customers Love This Gemstone

• GIA Untreated Confirmation: The most authoritative verification in the gemstone world — no treatment, no exception.
• True Rarity: Untreated ruby above 1.5 carats is one of the rarest gem categories available commercially.
• Investment Grade: Untreated, GIA-documented, above 1.5 carats — the specification that defines collector-level ruby.
• Trusted Source: Every claim independently confirmed, nothing undisclosed.

Owning this 1.83 ct untreated GIA cushion ruby means acquiring one of the genuinely rare gemstones in the colored stone market — a stone whose natural color and Madagascar origin are confirmed by the world's most recognized laboratory (Report #6233835340).

Perfect Uses for this 1.83 ct Untreated Ruby

• Investment-grade gemstone collection
• Statement engagement ring center stone
• Collectors of GIA-documented untreated ruby
• Heirloom-quality custom commission
• Significant anniversary or milestone gift