Tanzanites striking blue-violet color is caused by the presence of trace amounts of vanadium within the mineral zoisite. When this vanadium-bearing zoisite is exposed to heateither naturally in the earth or through gentle heating after miningthe stones color shifts to the vivid shades of blue and violet that make tanzanite so sought after. This heat treatment is standard and widely accepted in the gemstone industry, and it is both permanent and stable.

Tanzanite is also pleochroic, meaning it displays different colors when viewed from different angles. In its natural crystal form, tanzanite can show blue, violet, or even burgundy and pink tones depending on the direction of light and how the gem is oriented. Skilled gem cutters play a major role in determining whether a tanzanite appears more blue or more violet. Because tanzanite is pleochroic, showing different colors from different angles, the cutter must carefully orient the rough material to bring out the most desirable hue. By adjusting the cutting angle and table orientation, they can highlight either the blue or the violet axis of the crystal. Cutting to emphasize the blue often results in more weight loss, since the rough may naturally favor the violet direction. For this reason, blue-dominant tanzanites are rarer and more valuable, and they are more likely to be found in larger sizes. This interplay of natural crystal structure and skilled cutting is part of what makes each tanzanite so distinctive.

The final color can also be influenced by carat weight and lighting conditions. Smaller stones often show more violet, while larger gems can display deeper blues. In natural daylight, the blue tones tend to dominate, whereas warm indoor lighting brings out more of the purple. This play of color adds to tanzanites unique charm and is one of the reasons it's considered a modern classic in fine jewelry.

Most of the tanzanite on the market today is natural, meaning it formed in the earth over millions of years, but nearly all of it has been heat treated to achieve its beautiful blue violet color. In its untreated state, tanzanite often shows more brown, yellow, or greenish tones. Gentle heating is used to remove these less desirable colors and bring out the vibrant blue and violet hues that tanzanite is known for. This treatment is standard, widely accepted in the industry, and considered permanent and stable.

The process works by altering the oxidation state of vanadium, a trace element within the crystal lattice. Heating causes electrons to be removed from vanadium, which changes how the crystal absorbs and reflects light. This shift in the atomic structure intensifies the gems color without affecting its chemical makeup or damaging the stone itself. In simple terms, the treatment enhances what nature already created, revealing the gem's most beautiful color.

Untreated, richly colored tanzanites are rare and generally only found in private collections or museums. Virtually all fine quality tanzanite available today has undergone this enhancement, and it is embraced by both gemologists and collectors alike.

When evaluating the quality of a tanzanite, the most important factors are color, clarity, cut, and size. The finest stones display a strong, saturated blue-violet hue with excellent balance and no gray or brown undertones. Some tanzanites lean more blue, others more violet, but the most valuable stones have rich intensity and even color distribution across the surface. You may also find tanzanite with a lighter lavender or pastel purple color, and while these are not considered top quality, they can still be exceptionally pretty and appealing. Ultimately, the best tanzanite is the one that speaks to you, whether it leans more blue, violet, or something in between.

Clarity is also key. High-quality tanzanite should be eye-clean, meaning it has no visible inclusions that distract from its appearance. Inclusions in tanzanite are relatively uncommon, but they can impact brilliance and transparency when present. Look for stones with a lively, open appearance and good light return.

Cut brings out the best in tanzanites pleochroic color play. Well-proportioned stones with crisp facets and proper symmetry will show vibrant flashes of blue and violet from different angles. Shapes like oval, cushion, and emerald cut are especially popular and highlight the gems color beautifully.

Size can also influence both appearance and value. Larger tanzanites tend to display deeper color saturation and stronger pleochroic effects, which makes them even more striking. At MyJewelrySource.com, we select tanzanite gemstones that offer an ideal combination of color, clarity, and craftsmanship to ensure lasting beauty and collector-level quality.

You may have seen tanzanite described using letter grades like AAA, AA, or even AAAA, but its important to understand that these terms are not standardized or regulated. Unlike the diamond industry, which uses universally accepted criteria to grade color, clarity, cut, and carat weight, colored gemstones like tanzanite are not governed by an official grading system. As a result, different jewelers may assign these letter grades based on their own interpretation, and the same stone might be labeled differently by different sellers.

In the past, AAA was commonly used to describe tanzanites with deep, vivid color and good clarity. But in recent years, marketing has taken over, and weve seen exaggerated terms like AAAA or museum grade that dont reflect any measurable difference. These labels can create confusion for buyers, especially when the grading is used to justify inflated prices.

Instead of relying on these subjective labels, its much more helpful to evaluate a tanzanite by its color, clarity, and cut directly. For the highest quality, look for tanzanite with rich saturation, strong blue-violet color, excellent clarity, and precise faceting that enhances the gems natural brilliance. That said, the most important factor is choosing a shade that speaks to you personally. At MyJewelrySource.com, we offer a range of beautiful tanzanite colorsfrom the finest deep violet-blues to medium tones and even some softer lavender hues. Whether you prefer bold and dramatic or delicate and airy, youll find a gem that fits your style and budget.