Counterfeit and imitation 真珠 are common — particularly online. この guide walks through tests you can do at home and signals to look for when buying.

Quick visual tests

1. The light test — rotate the 真珠 under direct light. 本物の 真珠 show subtle 色 shifts (オーバートーン); imitations show flat 均一の 色.
2. The temperature test — 本物の 真珠 feel slightly cool on 初回 お問い合わせ, then warm to body temperature. Plastic imitations stay at room temperature.
3. The 表面 test — under magnification, 本物の 真珠 show subtle 天然 不完全 (小 marks, growth lines). Imitations are perfectly 均一の.
4. The weight test — 本物の 真珠 feel heavier than それら look. Plastic imitations feel light.

The tooth test (delicate)

Gently rub the 真珠 基準 your front tooth. 本物の 真珠 feel slightly gritty due to the layered 真珠層 組織. Imitations feel 完全に smooth. Use この test sparingly — too aggressive お問い合わせ can damage 真珠層.

The 穴あけ hole test

Look at the 穴あけ hole under magnification. 本物の 養殖真珠 show: a clear distinction 間 the inner bead nucleus and the outer 真珠層 layer; the 真珠層 layer 推奨 be 目視可能な as a distinct バンド of 0.5-6mm. Plastic imitations have 均一の 色 through the 穴あけ hole.

何 to ask the seller

1. 何 species of 貝 produced the 真珠? (例:, Pinctada margaritifera for タヒチ, Pinctada maxima for 南洋)
2. 何 is the 専用の 産地 (ラグーン, atoll, or 養殖場 名前)?
3. 何 グレード is the 真珠, and 何 does that グレード 具体的に mean?
4. Is the 色 天然 or 処理済み/染色済み?
5. Is そこに a 鑑別書?

Red flags

• Prices significantly below industry benchmarks (see our buying guides)
• Vague 産地 claims ("from the Pacific" instead of "Marutea Atoll, フランス領ポリネシア")
• "Cultured" 真珠 priced below 典型的な 天然 真珠 thresholds — likely freshwater 染色済み to look like saltwater
• Sellers without 返品 policies
• Photos that look identical for many products (suggests 在庫 images, not actual product 写真)
• "本物" 真珠 without species identification

Common imitation types

• Glass beads with shell coating — 通常 Chinese-産地; weight similar to 本物の but 均一の 色
• Plastic beads with pearlescent coating — lightweight, 均一の, 完璧な spherical shape
• Mother-of-真珠 (shell) beads — denser than plastic but still 均一の 色; popular in costume jewelry
• 染色済み 淡水真珠 — actual 真珠 but artificially colored; often sold as "タヒチ-style"
• Plastic with 真珠 essence coating — bargain-basement imitations; brittle and easily damaged

Professional authentication

For 高い-value 真珠 ($5,000+), professional appraisal is recommended:

• GIA (Gemological Institute of America) — 問題 certificates; gold standard
• SSEF (Swiss Gemmological Institute) — internationally recognized
• GIT (Gem and Jewelry Institute of Thailand) — Asia-focused
• PSL (真珠 Science Lab 日本) — specializes in アコヤ certification

Our authentication commitment

全ての ピース sold by The 南洋真珠 発送 with a 鑑別書 documenting the species, 産地, グレード, and date of harvest where 利用可能. We グレード 基準 industry-consensus standards.

よくあるご質問

Can a 本物の 真珠 be stamped or marked?

いいえ、 individual 真珠 cannot be marked. Authentication relies on certificates, professional appraisal, and physical tests like the temperature and tooth tests.

How can I tell if a 真珠 is 染色済み?

染色済み 真珠 show flat 均一の 色 instead of 天然 オーバートーン shifts. Reputable sellers always disclose dyeing. If a ブラック 真珠 is priced below $50, it is almost certainly 染色済み.

何 is the ほとんど common 種類 of 真珠 counterfeit?

染色済み 淡水真珠 sold as "タヒチ" or "南洋" 真珠. These are actual 真珠 but artificially colored to mimic premium 真珠 appearance.

推奨 I send a 真珠 to GIA for certification?

For 高い-value 真珠 ($3,000+) intended for resale, 保険, or estate planning, はい. For personal jewelry, our 鑑別書 is 通常 sufficient.

How does the tooth test work?

本物の 真珠 have microscopic layers of aragonite that 作成 a subtle gritty texture. Imitations are perfectly smooth (plastic) or uniformly coated (glass). Use the test sparingly to 避ける 表面 damage.